JP4067875B2 - Repair method and manufacturing method of active matrix light-emitting device - Google Patents

Description

【０１４６】
(M.A.Baldo, D.F.O'Brien, Y.You, A.Shoustikov, S.Sibley, M.E.Thompson, S.R.Forrest, Nature 395 (1998) p.151.)
【０１４７】
上記の論文により報告された発光素子の材料（Ｐｔ錯体）の分子式を以下に示す。
【０１４８】
【化２】

【０１４９】
(M.A.Baldo, S.Lamansky, P.E.Burrrows, M.E.Thompson, S.R.Forrest, Appl.Phys.Lett.,75 (1999) p.4.) (T.Tsutsui, M.-J.Yang, M.Yahiro, K.Nakamura, T.Watanabe, T.tsuji, Y.Fukuda, T.Wakimoto, S.Mayaguchi, Jpn.Appl.Phys., 38 (12B) (1999) L1502.)
【０１５０】
上記の論文により報告された発光素子の材料（Ｉｒ錯体）の分子式を以下に示す。
【０１５１】
【化３】

【０１５２】
以上のように三重項励起子からの燐光発光を利用できれば原理的には一重項励起子からの蛍光発光を用いる場合より３〜４倍の高い外部発光量子効率の実現が可能となる。
【０１５３】
なお、本実施例の構成は、実施例１〜実施例４のいずれの構成とも自由に組み合わせて実施することが可能である。
【０１５４】
（実施例６）
本実施例では、本発明の修理方法を用いた発光装置の断面図について説明する。
【０１５５】
図１４において、基板７００上に設けられたスイッチング用ＴＦＴ７２１はｎチャネル型ＴＦＴ５０３を用いて形成される。
【０１５６】
なお、本実施例ではスイッチング用ＴＦＴ７２１がチャネル形成領域が二つ形成されるダブルゲート構造としているが、チャネル形成領域が一つ形成されるシングルゲート構造もしくは三つ形成されるトリプルゲート構造であっても良い。
【０１５７】
基板７００上に設けられた駆動回路はｎチャネル型ＴＦＴ７２３とｐチャネル型ＴＦＴ７２４を有している。なお、本実施例では駆動回路が有するＴＦＴをシングルゲート構造としているが、ダブルゲート構造もしくはトリプルゲート構造であっても良い。
【０１５８】
また、配線７０１、７０３はＣＭＯＳ回路のソース配線、７０２はドレイン配線として機能する。また、配線７０４はソース配線７０８とスイッチング用ＴＦＴのソース領域とを電気的に接続する配線として機能し、配線７０５はドレイン配線７０９とスイッチング用ＴＦＴのドレイン領域とを電気的に接続する配線として機能する。
【０１５９】
なお、駆動用ＴＦＴ７２２はｐチャネル型ＴＦＴを用いて形成される。なお、本実施例では駆動用ＴＦＴ７２２をシングルゲート構造としているが、ダブルゲート構造もしくはトリプルゲート構造であっても良い。
【０１６０】
また、配線７０６は駆動用ＴＦＴのソース配線（電流供給線に相当する）であり、７０７は駆動用ＴＦＴの画素電極７１０上に重ねることで画素電極７１０と電気的に接続する電極である。
【０１６１】
なお、７１０は、透明導電膜からなる画素電極（有機発光素子の陽極）である。透明導電膜としては、酸化インジウムと酸化スズとの化合物、酸化インジウムと酸化亜鉛との化合物、酸化亜鉛、酸化スズまたは酸化インジウムを用いることができる。また、前記透明導電膜にガリウムを添加したものを用いても良い。画素電極７１０は、上記配線を形成する前に平坦な層間絶縁膜７１１上に形成する。本実施例においては、樹脂からなる平坦化膜７１１を用いてＴＦＴによる段差を平坦化することは非常に重要である。後に形成される有機化合物層は非常に薄いため、段差が存在することによって発光不良を起こす場合がある。従って、有機化合物層をできるだけ平坦面に形成しうるように画素電極を形成する前に平坦化しておくことが望ましい。
【０１６２】
配線７０１〜７０７を形成後、図１４に示すようにバンク７１２を形成する。バンク７１２は１００〜４００ｎｍの珪素を含む絶縁膜もしくは有機樹脂膜をパターニングして形成すれば良い。
【０１６３】
画素電極７１０の上には有機化合物層７１３が形成される。なお、図１４では一画素しか図示していないが、本実施例ではＲ（赤）、Ｇ（緑）、Ｂ（青）の各色に対応した有機化合物層を作り分けている。また、本実施例では蒸着法により低分子系有機化合物層を形成している。具体的には、正孔注入層７１３ａとして２０ｎｍ厚の銅フタロシアニン（ＣｕＰｃ）膜を設け、その上に発光層７１３ｂとして７０ｎｍ厚のトリス−８−キノリノラトアルミニウム錯体（Ａｌｑ₃）膜を設けた積層構造としている。Ａｌｑ₃にキナクリドン、ペリレンもしくはＤＣＭ１といった蛍光色素を添加することで発光色を制御することができる。
【０１６４】
但し、以上の例は有機化合物層として用いることのできる有機化合物材料の一例であって、これに限定する必要はまったくない。発光層、電荷輸送層または電荷注入層を自由に組み合わせて有機化合物層（発光及びそのためのキャリアの移動を行わせるための層）を形成すれば良い。例えば、本実施例では低分子系有機化合物材料を有機化合物層として用いる例を示したが、高分子系有機化合物材料を用いても良い。また、電荷輸送層や電荷注入層として炭化珪素等の無機材料を用いることも可能である。これらの有機材料や無機材料は公知の材料を用いることができる。
【０１６５】
次に、有機化合物層７１３の上には導電膜からなる陰極７１４が設けられる。本実施例の場合、導電膜としてアルミニウムとマグネシウムとの合金膜を用いる。勿論、公知のＭｇＡｇ膜（マグネシウムと銀との合金膜）を用いても良い。陰極材料としては、周期表の２族に属する元素からなる導電膜もしくはそれらの元素を添加した導電膜を用いても良い。例えば、Ｂｅ、Ｍｇ、Ｃａ、Ｓｒ、Ｂａのうち少なくとも一つを添加する。
【０１６６】
なお、陰極を二層の膜を積層した構造とし、有機化合物層に接してマグネシウムを形成し、マグネシウム上にアルミニウムを形成した構成とすると有機発光素子が発光を開始する電圧を低減することができる。このとき、マグネシウムは１０ｎｍ厚、アルミニウムは１００ｎｍ厚とすることが好ましい。
【０１６７】
この陰極７１４まで形成された時点で有機発光素子７１９が完成する。なお、ここでいう有機発光素子７１９は、画素電極（陽極）７１０、有機化合物層７１３及び陰極７１４で形成されたコンデンサを指す。
【０１６８】
有機発光素子７１９を完全に覆うようにしてパッシベーション膜７１６を設けることは有効である。パッシベーション膜７１６としては、炭素膜、窒化珪素膜もしくは窒化酸化珪素膜を含む絶縁膜からなり、該絶縁膜を単層もしくは組み合わせた積層で用いる。
【０１６９】
この際、カバレッジの良い膜をパッシベーション膜として用いることが好ましく、炭素膜、特にＤＬＣ（ダイヤモンドライクカーボン）膜を用いることは有効である。ＤＬＣ膜は室温から１００℃以下の温度範囲で成膜可能であるため、耐熱性の低い有機化合物層７１３の上方にも容易に成膜することができる。また、ＤＬＣ膜は酸素に対するブロッキング効果が高く、有機化合物層７１３の酸化を抑制することが可能である。そのため、この後に続く封止工程を行う間に有機化合物層７１３が酸化するといった問題を防止できる。
【０１７０】
さらに、パッシベーション膜７１６上に封止材７１７を設け、カバー材７１８を貼り合わせる。封止材７１７としては紫外線硬化樹脂を用いれば良く、内部に吸湿効果を有する物質もしくは酸化防止効果を有する物質を設けることは有効である。また、本実施例においてカバー材７１８はガラス基板や石英基板やプラスチック基板（プラスチックフィルムも含む）の両面に炭素膜（好ましくはダイヤモンドライクカーボン膜）を形成したものを用いる。
【０１７１】
こうして図１４に示すような構造の発光装置が完成する。なお、バンク７１２を形成した後、パッシベーション膜７１６を形成するまでの工程をマルチチャンバー方式（またはインライン方式）の成膜装置を用いて、大気解放せずに連続的に処理することは有効である。また、さらに発展させてカバー材７１８を貼り合わせる工程までを大気解放せずに連続的に処理することも可能である。
【０１７２】
また、本実施例におけるＴＦＴの特徴は、ゲート電極が２層の導電膜から形成されており、そしてチャネル形成領域とドレイン領域との間に設けられる低濃度不純物領域において、ほとんど濃度差がなく、緩やかな濃度勾配を有し、下層のゲート電極と重なる領域（ＧＯＬＤ領域）と、ゲート電極と重ならない領域（ＬＤＤ領域）とを備えている点である。また、ゲート絶縁膜の周縁部、即ち、ゲート電極と重ならない領域及び高濃度不純物領域の上方の領域はテーパー状となっている。
【０１７３】
本実施例の発光装置において発光層７１３ｂにピンホールが形成されていると、該ピンホールを介して正孔注入層７１３ａと陰極７１４とが接触している欠陥部が形成される。本発明の修理方法により、該欠陥部を変性部７１５に変えることで抵抗を高くすることができる。よって、画素のピンホール以外の部分の輝度を高くし、ピンホールの周りの有機化合物層の劣化が促進されるのを防ぐことができる。
【０１７４】
また、本実施例では画素部と駆動回路の構成のみ示しているが、本実施例の製造工程に従えば、その他にも信号分割回路、Ｄ／Ａコンバータ、オペアンプ、γ補正回路などの論理回路を同一の絶縁体上に形成可能であり、さらにはメモリやマイクロプロセッサをも形成しうる。
【０１７５】
なお本実施例の構成は、実施例１、２、３または８と自由に組み合わせて実施することが可能である。
（実施例７）
本実施例では、本発明の修理方法を用いた発光装置の断面図について説明する。
【０１７６】
図１５において、同一の基板上に、駆動回路のｐチャネル型ＴＦＴ２００と、ｎチャネル型ＴＦＴ２０１と、画素部の駆動用ＴＦＴ２０３と、スイッチング用ＴＦＴ２０４と、保持容量とが形成されている。
【０１７７】
駆動回路のｐチャネル型ＴＦＴ２００には、第２のテーパー形状を有する導電層２２０がゲート電極としての機能を有し、また、チャネル形成領域２０６、ソース領域またはドレイン領域として機能する第３の不純物領域２０７ａ、ゲート電極２２０と重ならないＬＤＤ領域を形成する第４の不純物領域（Ａ）２０７ｂ、一部がゲート電極２２０と重なるＬＤＤ領域を形成する第４の不純物領域（Ｂ）２０７ｃを有する構造となっている。
【０１７８】
ｎチャネル型ＴＦＴ２０１には、第２のテーパー形状を有する導電層２２１がゲート電極としての機能を有し、また、チャネル形成領域２０８、ソース領域またはドレイン領域として機能する第１の不純物領域２０９ａ、ゲート電極２２１と重ならないＬＤＤ領域を形成する第２の不純物領域（Ａ）（Ａ）２０９ｂ、一部がゲート電極２２１と重なるＬＤＤ領域を形成する第２の不純物領域（Ｂ）２０９ｃを有する構造となっている。チャネル長２〜７μｍに対して、第２の不純物領域（Ｂ）２０９ｃがゲート電極２２１と重なる部分の長さは０．１〜０．３μｍとする。このＬovの長さはゲート電極２２１の厚さとテーパー部の角度から制御する。ｎチャネル型ＴＦＴにおいてこのようなＬＤＤ領域を形成することにより、ドレイン領域近傍に発生する高電界を緩和して、ホットキャリアの発生を防ぎ、ＴＦＴの劣化を防止することができる。
【０１７９】
駆動用ＴＦＴ２０３は同様に、第２のテーパー形状を有する導電層２２３がゲート電極としての機能を有し、また、チャネル形成領域２１２、ソース領域またはドレイン領域として機能する第３の不純物領域２１３ａ、ゲート電極２２３と重ならないＬＤＤ領域を形成する第４の不純物領域（Ａ）２１３ｂ、一部がゲート電極２２３と重なるＬＤＤ領域を形成する第４の不純物領域（Ｂ）２１３ｃを有する構造となっている。
【０１８０】
駆動回路はシフトレジスタ回路、バッファ回路などのロジック回路やアナログスイッチで形成されるサンプリング回路などで形成される。図１５ではこれらを形成するＴＦＴを一対のソース・ドレイン間に一つのゲート電極を設けたシングルゲートの構造で示したが、複数のゲート電極を一対のソース・ドレイン間に設けたマルチゲート構造としても差し支えない。
【０１８１】
駆動用ＴＦＴ２０３のドレイン領域は配線２３１を介して画素電極２７１に接続されている。画素電極２７１に接するように公知の有機化合物材料からなる有機化合物層２７２が形成されており、有機化合物層２７２に接するように陰極２７３が形成されている。
【０１８２】
スイッチング用ＴＦＴ２０４には、第２のテーパー形状を有する導電層２２４がゲート電極としての機能を有し、また、チャネル形成領域２１４ａ、２１４ｂ、ソース領域またはドレイン領域として機能する第１の不純物領域２１５ａ、２１７、ゲート電極２２４と重ならないＬＤＤ領域を形成する第２の不純物領域（Ａ）２１５ｂ、一部がゲート電極２２４と重なるＬＤＤ領域を形成する第２の不純物領域（Ｂ）２１５ｃを有する構造となっている。第２の不純物領域（Ｂ）２１３ｃがゲート電極２２４と重なる部分の長さは０．１〜０．３μｍとする。また、第１の不純物領域２１７から延在し、第２の不純物領域（Ａ）２１９ｂ、第２の不純物領域（Ｂ）２１９ｃ、導電型を決定する不純物元素が添加されていない領域２１８を有する半導体層と、第３の形状を有するゲート絶縁膜と同層で形成される絶縁層と、第２のテーパー形状を有する導電層から形成される容量配線２２５から保持容量が形成されている。
【０１８３】
本実施例の発光装置において有機化合物層２７２にピンホールが形成されていると、該ピンホールを介して画素電極２７１と陰極２７３とが接触している欠陥部が形成される。本発明の修理方法により、該欠陥部を変性部２７４に変えることで抵抗を高くすることができる。よって、画素のピンホール以外の部分の輝度を高くし、ピンホールの周りの有機化合物層の劣化が促進されるのを防ぐことができる。
【０１８４】
なお本実施例の構成は、実施例１、２、３または８と自由に組み合わせて実施することが可能である。
【０１８５】
（実施例８）
本実施例では、本発明の修理方法を用いた発光装置の断面図について説明する。
【０１８６】
図１６において、８１１は基板、８１２は下地となる絶縁膜（以下、下地膜という）である。基板８１１としては透光性基板、代表的にはガラス基板、石英基板、ガラスセラミックス基板、又は結晶化ガラス基板を用いることができる。但し、作製プロセス中の最高処理温度に耐えるものでなくてはならない。
【０１８７】
また、下地膜８１２は特に可動イオンを含む基板や導電性を有する基板を用いる場合に有効であるが、石英基板には設けなくても構わない。下地膜８１２としては、珪素（シリコン）を含む絶縁膜を用いれば良い。なお、本明細書において「珪素を含む絶縁膜」とは、具体的には酸化珪素膜、窒化珪素膜若しくは窒化酸化珪素膜（ＳｉＯｘＮｙ：ｘ、ｙは任意の整数、で示される）など珪素に対して酸素若しくは窒素を所定の割合で含ませた絶縁膜を指す。
【０１８８】
８２０１はスイッチング用ＴＦＴ、８２０２は駆動用ＴＦＴであり、それぞれｎチャネル型ＴＦＴ、ｐチャネル型ＴＦＴで形成されている。有機化合物層で生じた光の発光方向が基板の下面（ＴＦＴ及び有機化合物層が設けられていない面）の場合、上記構成であることが好ましい。しかし本願発明はこの構成に限定されない。スイッチング用ＴＦＴと駆動用ＴＦＴは、ｎチャネル型ＴＦＴでもｐチャネル型ＴＦＴでも、どちらでも構わない。
【０１８９】
スイッチング用ＴＦＴ８２０１は、ソース領域８１３、ドレイン領域８１４、ＬＤＤ領域８１５a〜８１５d、分離領域８１６及びチャネル形成領域８１７a、８１７bを含む活性層と、ゲート絶縁膜８１８と、ゲート電極８１９a、８１９bと、第１層間絶縁膜８２０と、ソース信号線８２１と、ドレイン配線８２２とを有している。なお、ゲート絶縁膜８１８又は第１層間絶縁膜８２０は基板上の全ＴＦＴに共通であっても良いし、回路又は素子に応じて異ならせても良い。
【０１９０】
また、図１６に示すスイッチング用ＴＦＴ８２０１はゲート電極８１７a、８１７bが電気的に接続されており、いわゆるダブルゲート構造となっている。勿論、ダブルゲート構造だけでなく、トリプルゲート構造などいわゆるマルチゲート構造（直列に接続された二つ以上のチャネル形成領域を有する活性層を含む構造）であっても良い。
【０１９１】
マルチゲート構造はオフ電流を低減する上で極めて有効であり、スイッチング用ＴＦＴのオフ電流を十分に低くすれば、それだけ駆動用ＴＦＴ８２０２のゲート電極に接続されたコンデンサが必要とする最低限の容量を抑えることができる。即ち、コンデンサの面積を小さくすることができるので、マルチゲート構造とすることは有機発光素子の有効発光面積を広げる上でも有効である。
【０１９２】
さらに、スイッチング用ＴＦＴ８２０１においては、ＬＤＤ領域８１５a〜８１５dは、ゲート絶縁膜８１８を介してゲート電極８１９a、８１９bと重ならないように設ける。このような構造はオフ電流を低減する上で非常に効果的である。また、ＬＤＤ領域８１５a〜８１５dの長さ（幅）は０．５〜３．５μｍ、代表的には２．０〜２．５μｍとすれば良い。
【０１９３】
なお、チャネル形成領域とＬＤＤ領域との間にオフセット領域（チャネル形成領域と同一組成の半導体層でなり、ゲート電圧が加えられない領域）を設けることはオフ電流を下げる上でさらに好ましい。また、二つ以上のゲート電極を有するマルチゲート構造の場合、チャネル形成領域の間に設けられた分離領域８１６（ソース領域又はドレイン領域と同一の濃度で同一の不純物元素が添加された領域）がオフ電流の低減に効果的である。
【０１９４】
次に、駆動用ＴＦＴ８２０２は、ソース領域８２６、ドレイン領域８２７及びチャネル形成領域８２９を含む活性層と、ゲート絶縁膜８１８と、ゲート電極８３０と、第１層間絶縁膜８２０と、ソース信号線８３１並びにドレイン配線８３２を有して形成される。本実施例において駆動用ＴＦＴ８２０２はｐチャネル型ＴＦＴである。
【０１９５】
また、スイッチング用ＴＦＴ８２０１のドレイン領域８１４は駆動用ＴＦＴ８２０２のゲート８３０に接続されている。図示してはいないが、具体的には駆動用ＴＦＴ８２０２のゲート電極８３０はスイッチング用ＴＦＴ８２０１のドレイン領域８１４とドレイン配線（接続配線とも言える）８２２を介して電気的に接続されている。なお、ゲート電極８３０はシングルゲート構造となっているが、マルチゲート構造であっても良い。また、駆動用ＴＦＴ８２０２のソース信号線８３１は電源供給線（図示せず）に接続される。
【０１９６】
駆動用ＴＦＴ８２０２は有機発光素子に注入される電流量を制御するための素子であり、比較的多くの電流が流れる。そのため、チャネル幅（Ｗ）はスイッチング用ＴＦＴのチャネル幅よりも大きく設計することが好ましい。また、駆動用ＴＦＴ８２０２に過剰な電流が流れないように、チャネル長（Ｌ）は長めに設計することが好ましい。望ましくは一画素あたり０．５〜２μＡ（好ましくは１〜１．５μＡ）となるようにする。
【０１９７】
またさらに、駆動用ＴＦＴ８２０２の活性層（特にチャネル形成領域）の膜厚を厚くする（好ましくは５０〜１００ｎｍ、さらに好ましくは６０〜８０ｎｍ）ことによって、ＴＦＴの劣化を抑えてもよい。逆に、スイッチング用ＴＦＴ８２０１の場合はオフ電流を小さくするという観点から見れば、活性層（特にチャネル形成領域）の膜厚を薄くする（好ましくは２０〜５０ｎｍ、さらに好ましくは２５〜４０ｎｍ）ことも有効である。
【０１９８】
以上は画素内に設けられたＴＦＴの構造について説明したが、このとき同時に駆動回路も形成される。図１６には駆動回路を形成する基本単位となるＣＭＯＳ回路が図示されている。
【０１９９】
図１６においては極力動作速度を落とさないようにしつつホットキャリア注入を低減させる構造を有するＴＦＴをＣＭＯＳ回路のｎチャネル型ＴＦＴ８２０４として用いる。なお、ここでいう駆動回路としては、ソース信号側駆動回路、ゲート信号側駆動回路を指す。勿論、他の論理回路（レベルシフタ、Ａ／Ｄコンバータ、信号分割回路等）を形成することも可能である。
【０２００】
ＣＭＯＳ回路のｎチャネル型ＴＦＴ８２０４の活性層は、ソース領域８３５、ドレイン領域８３６、ＬＤＤ領域８３７及びチャネル形成領域８３８を含み、ＬＤＤ領域８３７はゲート絶縁膜８１８を介してゲート電極８３９と重なっている。
【０２０１】
ドレイン領域８３６側のみにＬＤＤ領域８３７を形成しているのは、動作速度を落とさないための配慮である。また、このｎチャネル型ＴＦＴ８２０４はオフ電流値をあまり気にする必要はなく、それよりも動作速度を重視した方が良い。従って、ＬＤＤ領域８３７は完全にゲート電極に重ねてしまい、極力抵抗成分を少なくすることが望ましい。即ち、いわゆるオフセットはなくした方がよい。
【０２０２】
また、ＣＭＯＳ回路のｐチャネル型ＴＦＴ８２０５は、ホットキャリア注入による劣化が殆ど気にならないので、特にＬＤＤ領域を設けなくても良い。従って活性層はソース領域８４０、ドレイン領域８４１及びチャネル形成領域８４２を含み、その上にはゲート絶縁膜８１８とゲート電極８４３が設けられる。勿論、ｎチャネル型ＴＦＴ８２０４と同様にＬＤＤ領域を設け、ホットキャリア対策を講じることも可能である。
【０２０３】
なお８６１〜８６５はチャネル形成領域８４２、８３８、８１７ａ、８１７ｂ、８２９を形成するためのマスクである。
【０２０４】
また、ｎチャネル型ＴＦＴ８２０４及びｐチャネル型ＴＦＴ８２０５はそれぞれソース領域上に第１層間絶縁膜８２０を間に介して、ソース信号線８４４、８４５を有している。また、ドレイン配線８４６によってｎチャネル型ＴＦＴ８２０４とｐチャネル型ＴＦＴ８２０５とのドレイン領域は互いに電気的に接続される。
【０２０５】
次に、８４７は第１パッシベーション膜であり、膜厚は１０ｎｍ〜１μm（好ましくは２００〜５００ｎｍ）とすれば良い。材料としては、珪素を含む絶縁膜（特に窒化酸化珪素膜又は窒化珪素膜が好ましい）を用いることができる。このパッシベーション膜８４７は形成されたＴＦＴをアルカリ金属や水分から保護する役割を有する。
【０２０６】
また、８４８は第２層間絶縁膜であり、ＴＦＴによってできる段差の平坦化を行う平坦化膜としての機能を有する。第２層間絶縁膜８４８としては、有機樹脂膜が好ましく、ポリイミド、ポリアミド、アクリル、ＢＣＢ（ベンゾシクロブテン）等を用いると良い。これらの有機樹脂膜は良好な平坦面を形成しやすく、比誘電率が低いという利点を有する。有機化合物層は凹凸に非常に敏感であるため、ＴＦＴによる段差は第２層間絶縁膜８４８で殆ど吸収してしまうことが望ましい。また、ゲート信号線やデータ信号線と有機発光素子の陰極との間に形成される寄生容量を低減する上で、比誘電率の低い材料を厚く設けておくことが望ましい。従って、膜厚は０．５〜５μm（好ましくは１．５〜２．５μm）が好ましい。
【０２０７】
また、８４９は透明導電膜でなる画素電極（有機発光素子の陽極）であり、第２層間絶縁膜８４８及び第１パッシベーション膜８４７にコンタクトホール（開孔）を開けた後、形成された開孔部において駆動用ＴＦＴ８２０２のドレイン配線８３２に接続されるように形成される。
【０２０８】
画素電極８４９の上には酸化珪素膜、窒化酸化珪素膜または有機樹脂膜でなる第３層間絶縁膜８５０が０．３〜１μmの厚さに設けられる。この第３層間絶縁膜８５０は画素電極８４９の上にエッチングにより開口部が設けられ、その開口部の縁はテーパー形状となるようにエッチングする。テーパーの角度は１０〜６０°（好ましくは３０〜５０°）とすると良い。
【０２０９】
第３層間絶縁膜８５０の上には有機化合物層８５１が設けられる。有機化合物層８５１は単層又は積層構造で用いられるが、積層構造で用いた方が発光効率は良い。一般的には画素電極上に正孔注入層／正孔輸送層／発光層／電子輸送層の順に形成されるが、正孔輸送層／発光層／電子輸送層、または正孔注入層／正孔輸送層／発光層／電子輸送層／電子注入層のような構造でも良い。本願発明では公知のいずれの構造を用いても良いし、有機化合物層に対して蛍光性色素等をドーピングしても良い。
【０２１０】
図１６の構造はＲＧＢに対応した三種類の有機発光素子を形成する方式を用いた場合の例である。なお、図１６には一つの画素しか図示していないが、同一構造の画素が赤、緑又は青のそれぞれの色に対応して形成され、これによりカラー表示を行うことができる。本願発明は発光方式に関わらず実施することが可能である。
【０２１１】
有機化合物層８５１の上には有機発光素子の陰極８５２が設けられる。陰極８５２としては、仕事関数の小さいマグネシウム（Ｍｇ）、若しくはカルシウム（Ｃａ）を含む材料を用いる。好ましくはＭｇＡｇ（ＭｇとＡｇをＭｇ：Ａｇ＝１０：１の重量比で混合した材料）でなる電極、又は、ＡｌＭｇ（ＭｇとＡｌをＭｇ：Ａｇ＝５：９５の重量比で混合した材料）でなる電極を用いれば良い。他にもＭｇＡｇＡｌ電極が挙げられる。
【０２１２】
なお、画素電極（陽極）８４９、有機化合物層８５１及び陰極８５２によって有機発光素子８２０６が形成される。
【０２１３】
有機化合物層８５１と陰極８５２とでなる積層体は、各画素で個別に形成する必要があるが、有機化合物層８５１は水分に極めて弱いため、通常のフォトリソグラフィ技術を用いることができない。従って、メタルマスク等の物理的なマスク材を用い、真空蒸着法、スパッタ法、プラズマＣＶＤ法等の気相法で選択的に形成することが好ましい。
【０２１４】
なお、有機化合物層を選択的に形成する方法として、インクジェット法、スクリーン印刷法又はスピンコート法等を用いることも可能であるが、これらは現状では陰極の連続形成ができないので、上述の方法の方が好ましいと言える。
【０２１５】
また、８５３は保護電極であり、陰極８５２を外部の水分等から保護すると同時に、各画素の陰極８５２を接続するための電極である。保護電極８５３としては、アルミニウム（Ａｌ）、銅（Ｃｕ）若しくは銀（Ａｇ）を含む低抵抗な材料を用いることが好ましい。この保護電極８５３には有機化合物層の発熱を緩和する放熱効果も期待できる。
【０２１６】
また、８５４は第２パッシベーション膜であり、膜厚は１０ｎｍ〜１μm（好ましくは２００〜５００ｎｍ）とすれば良い。第２パッシベーション膜８５４を設ける目的は、有機化合物層８５１を水分から保護する目的が主であるが、放熱効果をもたせることも有効である。但し、上述のように有機化合物層は熱に弱いので、なるべく低温（好ましくは室温から１２０℃までの温度範囲）で成膜するのが望ましい。従って、プラズマＣＶＤ法、スパッタ法、真空蒸着法、イオンプレーティング法又は溶液塗布法（スピンコーティング法）が望ましい成膜方法と言える。
【０２１７】
なお、図１６に図示されたＴＦＴは全て、本願発明で用いるポリシリコン膜を活性層として有していても良いことは言うまでもない。
【０２１８】
本実施例の発光装置において有機化合物層８６０にピンホールが形成されていると、該ピンホールを介して画素電極８４９と陰極８５２とが接触している欠陥部が形成される。本発明の修理方法により、該欠陥部を変性部８６０に変えることで抵抗を高くすることができる。よって、画素のピンホール以外の部分の輝度を高くし、ピンホールの周りの有機化合物層の劣化が促進されるのを防ぐことができる。
【０２１９】
なお本実施例の構成は、実施例１、２、３または８と自由に組み合わせて実施することが可能である。
【０２２０】
（実施例９）
有機発光素子を用いた発光装置は自発光型であるため、液晶表示装置に比べ、明るい場所での視認性に優れ、視野角が広い。従って、様々な電子機器の表示部に用いることができる。
【０２２１】
本発明の修理方法を用いた発光装置を用いた電子機器として、ビデオカメラ、デジタルカメラ、ゴーグル型ディスプレイ（ヘッドマウントディスプレイ）、ナビゲーションシステム、音響再生装置（カーオーディオ、オーディオコンポ等）、ノート型パーソナルコンピュータ、ゲーム機器、携帯情報端末（モバイルコンピュータ、携帯電話、携帯型ゲーム機または電子書籍等）、記録媒体を備えた画像再生装置（具体的にはデジタルビデオディスク（ＤＶＤ）等の記録媒体を再生し、その画像を表示しうる表示装置を備えた装置）などが挙げられる。特に、斜め方向から画面を見る機会が多い携帯情報端末は、視野角の広さが重要視されるため、有機発光素子を有する発光装置を用いることが望ましい。それら電子機器の具体例を図１１に示す。
【０２２２】
図１１（Ａ）は表示装置であり、筐体２００１、支持台２００２、表示部２００３、スピーカー部２００４、ビデオ入力端子２００５等を含む。本発明の修理方法を用いて作製された発光装置は表示部２００３に用いることができる。有機発光素子を有する発光装置は自発光型であるためバックライトが必要なく、液晶表示装置よりも薄い表示部とすることができる。なお、表示装置は、パソコン用、ＴＶ放送受信用、広告表示用などの全ての情報表示用表示装置が含まれる。
【０２２３】
図１１（Ｂ）はデジタルスチルカメラであり、本体２１０１、表示部２１０２、受像部２１０３、操作キー２１０４、外部接続ポート２１０５、シャッター２１０６等を含む。本発明の修理方法を用いて作製された発光装置は表示部２１０２に用いることができる。
【０２２４】
図１１（Ｃ）はノート型パーソナルコンピュータであり、本体２２０１、筐体２２０２、表示部２２０３、キーボード２２０４、外部接続ポート２２０５、ポインティングマウス２２０６等を含む。本発明の修理方法を用いた発光装置は表示部２２０３に用いることができる。
【０２２５】
図１１（Ｄ）はモバイルコンピュータであり、本体２３０１、表示部２３０２、スイッチ２３０４、操作キー２３０５、赤外線ポート２３０５等を含む。本発明の修理方法を用いた発光装置は表示部２３０２に用いることができる。
【０２２６】
図１１（Ｅ）は記録媒体を備えた携帯型の画像再生装置（具体的にはＤＶＤ再生装置）であり、本体２４０１、筐体２４０２、表示部Ａ２４０３、表示部Ｂ２４０４、記録媒体（ＤＶＤ等）読み込み部２４０５、操作キー２４０６、スピーカー部２４０７等を含む。表示部Ａ２４０３は主として画像情報を表示し、表示部Ｂ２４０４は主として文字情報を表示するが、本発明の修理方法を用いた発光装置はこれら表示部Ａ、Ｂ２４０３、２４０４に用いることができる。なお、記録媒体を備えた画像再生装置には家庭用ゲーム機器なども含まれる。
【０２２７】
図１１（Ｆ）はゴーグル型ディスプレイ（ヘッドマウントディスプレイ）であり、本体２５０１、表示部２５０２、アーム部２５０３を含む。本発明の修理方法を用いた発光装置は表示部２５０２に用いることができる。
【０２２８】
図１１（Ｇ）はビデオカメラであり、本体２６０１、表示部２６０２、筐体２６０３、外部接続ポート２６０４、リモコン受信部２６０５、受像部２６０６、バッテリー２６０７、音声入力部２６０８、操作キー２６０９等を含む。本発明の修理方法を用いた発光装置は表示部２６０２に用いることができる。
【０２２９】
ここで図１１（Ｈ）は携帯電話であり、本体２７０１、筐体２７０２、表示部２７０３、音声入力部２７０４、音声出力部２７０５、操作キー２７０６、外部接続ポート２７０７、アンテナ２７０８等を含む。本発明の修理方法を用いた発光装置は表示部２７０３に用いることができる。なお、表示部２７０３は黒色の背景に白色の文字を表示することで携帯電話の消費電力を抑えることができる。
【０２３０】
なお、将来的に有機化合物材料の発光輝度が高くなれば、出力した画像情報を含む光をレンズ等で拡大投影してフロント型若しくはリア型のプロジェクターに用いることも可能となる。
【０２３１】
また、上記電子機器はインターネットやＣＡＴＶ（ケーブルテレビ）などの電子通信回線を通じて配信された情報を表示することが多くなり、特に動画情報を表示する機会が増してきている。有機化合物材料の応答速度は非常に高いため、発光装置は動画表示に好ましい。
【０２３２】
また、発光装置は発光している部分が電力を消費するため、発光部分が極力少なくなるように情報を表示することが望ましい。従って、携帯情報端末、特に携帯電話や音響再生装置のような文字情報を主とする表示部に発光装置を用いる場合には、非発光部分を背景として文字情報を発光部分で形成するように駆動することが望ましい。
【０２３３】
以上の様に、本発明の修理方法を用いた発光装置の適用範囲は極めて広く、あらゆる分野の電子機器に用いることが可能である。また、本実施例の電子機器は実施例１〜７に示したいずれの構成を用いても良い。
【０２３４】
（実施例１０）
本実施例では、本発明の修理方法をパッシブ型（単純マトリクス型）の発光装置に適用した場合について説明する。
【０２３５】
図２０（Ａ）にパッシブ型の発光装置の構成を示す。９０５は画素部であり、複数の画素９０６を有している。各画素は複数のデータ線９０３の１つと、複数の走査線９０４の１つとを有している。データ線９０３と走査線９０４の間に有機化合物層が形成されており、データ線９０３と走査線９０４とが電極となり、有機発光素子９０７が形成されている。
【０２３６】
データ線９０３に入力される信号はデータ線駆動回路９０１において制御されており、走査線９０４に入力される信号は走査線駆動回路９０２において制御されている。
【０２３７】
図２０（Ｂ）に、本発明の修理方法を用いたときに、走査線９０４とデータ線９０３に入力される信号の電圧の高さを示す。各走査線９０４の電圧を一定にし、データ線の電圧を一定期間毎に変化させることで、一定期間毎に有機発光素子９０７に所定の逆バイアスの電流を流す。
【０２３８】
なお有機発光素子９０７の欠陥の修理は、画素部９０５が有する全ての画素９０６において一斉に行っても良いし、各ライン毎、または各画素毎に行っても良い。
【０２３９】
本発明の方法を用いることによって、有機化合物層成膜時にゴミ等の影響によりピンホールが形成され、有機化合物層を間に挟んで形成された２つの層どうしがショートしても、ショートしている欠陥部の抵抗を高めることができ、有機発光素子に順バイアスの電圧をかけたときに実際に有機化合物層に流れる電流を大きくすることができる。したがって、本発明の修理方法により、欠陥部が存在しても、同じ電圧を印加したときの発光輝度を高くすることができる。
【０２４０】
また、欠陥部では常に電流が流れるために、欠陥部の周囲に存在する有機化合物層の劣化が促進されやすかった。しかし、変性層は抵抗Ｒ_SCが高いので電流は流れにくく、変性層の周囲に存在する有機化合物層の劣化が促進されることを防ぐことができる。
【０２４１】
本実施例は、実施例４、５、９と自由に組み合わせて実施することが可能である。
【０２４２】
【発明の効果】
本発明は上記構成によって、有機化合物層成膜時にゴミ等の影響によりピンホールが形成され、有機化合物層を間に挟んで形成された２つの層どうしがショートしても、ショートしている欠陥部の抵抗を高めることができ、有機発光素子に順バイアスの電圧をかけたときに実際に有機化合物層に流れる電流を大きくすることができる。したがって、本発明の修理方法により、欠陥部が存在しても、同じ電圧を印加したときの発光輝度を高くすることができる。
【０２４３】
また、欠陥部では常に電流が流れるために、欠陥部の周囲に存在する有機化合物層の劣化が促進されやすかった。しかし、変性層は抵抗Ｒ_SCが高いので電流は流れにくく、変性層の周囲に存在する有機化合物層の劣化が促進されることを防ぐことができる。
【０２４４】
さらに、有機発光素子の陰極にＮａ、Ｌｉを極力含まないようにすることで、有機発光素子に逆バイアスを加えたときに、有機発光素子、ＴＦＴといったデバイスを汚染することを防止できる。
【図面の簡単な説明】
【図１】 有機発光素子に逆バイアスの電圧を印加した時の、有機発光素子における電流の流れを模式的に示した図。
【図２】 修理の過程における有機発光素子の電圧電流特性の変化と、修理後の有機発光素子に順バイアスの電圧を印加した時の、有機発光素子における電流の流れを模式的に示した図。
【図３】 実施例１の画素の回路図。
【図４】 実施例１の画素部の回路図及び修理の際の画素部の動作を示す図。
【図５】 実施例２の画素の回路図。
【図６】 実施例２の画素部の回路図及び修理の際の画素部の動作を示す図。
【図７】 実施例３の画素部の回路図及び修理の際の画素部の動作を示す図。
【図８】 実施例３の画素の回路図。
【図９】 実施例４の有機発光素子の構成を示す図。
【図１０】 実施例４の有機発光素子の構成を示す図。
【図１１】 実施例１０の本発明の修理方法を用いた発光装置を有する電子機器。
【図１２】 欠陥部を有する有機発光素子の断面図と、該有機発光素子に順バイアスの電流を流したときの電流の流れを模式的に示した図。
【図１３】 有機発光素子の電圧−電流特性を示す図。
【図１４】 実施例５の発光装置の断面図。
【図１５】 実施例６の発光装置の断面図。
【図１６】 実施例７の発光装置の断面図。
【図１７】 ＡｌＭｇを電極としたＭＯＳ構造及び容量−電圧特性を示す図。
【図１８】 ＭｇＡｇを電極としたＭＯＳ構造及び容量−電圧特性を示す図。
【図１９】 ＡｌＬｉを電極としたＭＯＳ構造及び容量−電圧特性を示す図。
【図２０】 パッシブ型の発光装置に本発明の修理方法を用いた場合の図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing a light emitting device, and a method for manufacturing a light emitting device using the repair method in an intermediate process. More specifically, the present invention relates to a method for repairing a light emitting device that applies a reverse bias to an organic light emitting element, and a method for manufacturing a light emitting device including the repair method.
[0002]
The light emitting device is a general term for an organic light emitting display in which an organic light emitting element formed on a substrate is sealed between the substrate and a cover material, and a module in which an IC is mounted on the organic light emitting display.
[0003]
[Prior art]
The organic light-emitting element emits light by itself, and thus has high visibility. The backlight necessary for a liquid crystal display (LCD) is not necessary and is optimal for thinning, and the viewing angle is not limited. Therefore, in recent years, light-emitting devices using organic light-emitting elements have attracted attention as electro-optical devices that replace CRTs and LCDs.
[0004]
An organic light emitting element has a layer (hereinafter, referred to as an organic compound layer) containing an organic compound that can obtain luminescence (Electro Luminescence) generated by applying an electric field, an anode layer, and a cathode layer. Luminescence includes luminescence when returning from the singlet excited state to the ground state (fluorescence) and luminescence when returning from the triplet excited state to the ground state (phosphorescence). The present invention can also be applied to a light emitting device using light emission.
[0005]
In the present specification, all layers provided between the anode and the cathode are defined as organic compound layers. Specifically, the organic compound layer includes a light emitting layer, a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, and the like. Basically, an organic light emitting device has a structure in which an anode / light emitting layer / cathode is laminated in this order. In addition to this structure, an anode / hole injection layer / light emitting layer / cathode and anode / hole injection It may have a structure in which layers / light-emitting layers / electron transport layers / cathodes are laminated in this order.
[0006]
In this specification, the light emission of the organic light emitting element is referred to as driving of the organic light emitting element. In this specification, a light-emitting element formed using an anode, an organic compound layer, and a cathode is referred to as an organic light-emitting element.
[0007]
The organic light-emitting element has high rectification characteristics. When the anode is set to a higher potential than the cathode, a current flows through the organic compound layer, and light emission occurs due to carrier recombination. On the other hand, when the anode is at a lower potential than the cathode, almost no current flows through the organic compound layer. Due to this diode structure, the organic light emitting element is also called an organic light emitting diode (OLED).
[0008]
[Problems to be solved by the invention]
In general, in an organic light emitting device, after forming either an anode or a cathode, an organic compound layer is formed in contact with the electrode, and the remaining one of the anode or cathode is in contact with the organic compound layer. It is made by forming.
[0009]
As a method for forming the organic compound layer, there are mainly a film forming method by vapor deposition and a film forming method by spin coating. In either method, when depositing electrodes and organic compound layers, clean the substrate in the clean room where the film is deposited or clean the substrate before depositing so that dust does not adhere to the substrate. Efforts such as thoroughgoing are made.
[0010]
However, in spite of the above efforts, dust or the like may adhere to the electrode or the like, and a hole (pinhole) may be formed in the formed organic compound layer. FIG. 12A simply shows a cross-sectional view of the organic light emitting element 200 when the two electrodes 201 and 202 are short-circuited. When a pinhole is opened in the organic compound layer 203, when the electrode 202 is formed on the organic compound layer 203, the two electrodes 201 and 202 may be connected in the pinhole and short-circuited (short-circuited). Hereinafter, a portion where two layers formed with the light emitting layer interposed therebetween are in contact with each other in a pinhole formed in the light emitting layer is referred to as a defect portion 204.
[0011]
FIG. 13A shows voltage-current characteristics of an organic light-emitting element having no defect, and FIG. 13B shows voltage-current characteristics of an organic light-emitting element short-circuited at the defect.
[0012]
13A and 13B are compared, the current flowing through the organic light emitting element 200 when a reverse bias voltage is applied to the organic light emitting element 200 is larger in the case of FIG. 13B.
[0013]
This is different from FIG. 13A, and in the case of FIG. 13B, since two electrodes are short-circuited in the defective portion 204, it is suggested that a current flows in the defective portion 204. .
[0014]
When the two electrodes 201 and 202 are short-circuited in the defect portion 204, the light emission luminance of the organic compound layer is lowered. FIG. 12B schematically shows a current flow when a forward bias voltage is applied to the organic light emitting element having a defect.
[0015]
When the two electrodes 201 and 202 are short-circuited in the defective portion 204, the defective portion 204 has a resistance R _SC It is considered that the two electrodes of the organic light emitting device 200 are connected to each other. Therefore, forward current I _ori When the current flows from one electrode of the organic light emitting device, the current flowing through the defect portion 204 is expressed as I _SC , The current flowing through the organic compound layer 203 is I _dio Then, the current I _ori = I _SC + I _dio Meet.
[0016]
Thus, the above formula I _ori = I _SC + I _dio I _ori Is constant, in an organic light-emitting device in which a defect exists, the current I actually flowing through the organic compound layer 203 is _dio Becomes smaller. Resistance R at the defect 204 _SC I becomes smaller _SC Therefore, this tendency becomes remarkable, and the rectifying property of the organic light emitting element 200 is further broken.
[0017]
Current I flowing in the organic compound layer 203 _dio When becomes smaller, the light emission luminance of the organic light emitting device 200 decreases. That is, when the defect is short-circuited, the light emission luminance of the organic light-emitting element when a forward bias voltage is applied is lower than when the short-circuit is not performed.
[0018]
Further, even when the organic compound layer is formed by laminating a plurality of layers, when a pinhole is formed in the light emitting layer, a hole injection layer or a hole transport layer through the pinhole, The electron injection layer or the electron transport layer is connected. The portion where the hole injection layer or hole transport layer and the electron injection layer or electron transport layer are connected is also in a state where a reverse bias current flows in the same manner as the defect portion where the electrode is short-circuited. This causes a decrease in the light emission luminance of the organic light emitting device. In the following description, all portions where two layers formed with the light emitting layer interposed therebetween are in contact with each other through a pinhole formed in the light emitting layer are collectively referred to as a defective portion. The defective portion is a portion where the anode and the cathode are electrically short-circuited.
[0019]
Furthermore, in addition to the decrease in the light emission luminance of the organic light emitting element, if the defect is short-circuited, a current always flows through the defect, which promotes the deterioration of the organic compound layer existing around the defect.
[0020]
In view of the above problems, an object of the present invention is to devise a method for repairing a defective portion.
[0021]
[Means for Solving the Problems]
The present inventor prevents a current flowing in an organic compound layer from being reduced when a forward bias voltage is applied, even if a defect portion is formed in the organic light emitting device, by increasing the resistance in the defect portion. I thought that I could do it.
[0022]
Therefore, a reverse bias voltage is applied to the organic light emitting device, and the reverse bias current I _rev , The resistance R in the defective part _SC Devised a way to increase
[0023]
Reverse bias current I for organic light emitting devices _rev Most of the flow does not flow to the organic compound layer, but flows to the short-circuited defect portion. Current I flowing through the defect _SC If it is large, the temperature of the defective part rises, so the defective part burns out, evaporates and evaporates, or oxidizes or carbonizes to become an insulator, and some change occurs in the defective part. Resistance R _SC Becomes larger. In this specification, resistance R can be obtained by applying a reverse bias current. _SC The defect portion with a large is called a modified layer.
[0024]
Resistance R _SC When a forward bias voltage is applied to the organic light emitting device, the current flowing through the modified layer decreases, and instead, the current flowing through the organic compound layer increases, resulting in an increase in light emission luminance.
[0025]
In addition, since a current always flows in the defect portion, the deterioration of the organic compound layer existing around the defect portion is easily promoted. However, the modified layer has a resistance R _SC Therefore, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer.
[0026]
Next, the material of the cathode of the organic light emitting device used in the present invention was examined. The cathode is preferably made of a material having a low work function because of electron injection, and includes materials such as Li and Mg. The effects of these materials were investigated.
[0027]
CV (capacitance-voltage) characteristics were examined using a sample having a MOS (Metal-Oxide-Silicon) structure. MOS capacitor C and insulating film capacitor C _OX The ratio is determined depending on the voltage. When a clean MOS with no impurities is used, C / C _OX Shows an ideal CV characteristic that is uniquely determined according to the voltage. A deviation from the ideal CV characteristic indicates that the MOS is contaminated with ionic impurities.
[0028]
Initial characteristics and characteristics after applying a bias of 1.7 MV / cm to the MOS at 150 ° C. for 1 hour were measured. The process of applying a bias while applying a thermal shock is called BT (bias-temperature) process. A process of applying a positive bias (+ BT process) and a process of applying a negative bias (-BT process) are performed with Si as the ground level.
[0029]
The CV characteristics were measured by setting Si at the ground level and increasing the electrode potential from -10V to + 10V and then from + 10V to -10V.
[0030]
The MOS structure has a structure in which a silicon oxide film is formed with a thickness of 50 nm on a silicon substrate, and AlMg, MgAg, or AlLi is formed as an electrode on the silicon oxide film. In the measurement, the weight ratio of AlMg was Al: Mg = 95: 5, MgAg was Mg: Ag = 90: 10, and AlLi was Al: Li = 90: 10.
[0031]
When AlMg is used as the electrode (FIG. 17) and when MgAg is used as the electrode (FIG. 18), both the initial characteristics and the characteristics after the BT treatment depend on the voltage. _OX The ideal characteristics that are uniquely determined. This shows that Mg diffusion was negligible even when thermal shock was applied.
[0032]
However, when AlLi was used as an electrode (FIG. 19), the CV characteristics were greatly deviated from the ideal values. In particular, the characteristic 600 after the BT process (+ BT process) for applying a positive bias greatly fluctuated with respect to the ideal value. This is because when LiLi is at a positive potential, Li ⁺ This is thought to be due to elution from the electrode due to electrical repulsion and diffusion. Even after initial characteristics and negative bias BT processing (-BT processing), a small amount of Li can be obtained by applying a positive voltage during measurement. ⁺ This is due to the elution of CV characteristics.
[0033]
For this reason, it has been concluded that an electrode to which highly diffusible Li is added is not preferable in terms of the configuration of the present invention in which the cathode is set to a positive potential when a reverse bias is applied to the organic light emitting device.
[0034]
Li contained in cathode by applying reverse bias ⁺ If it elutes, the device is contaminated while correcting the defective part by applying a reverse bias. Li eluted from the cathode ⁺ Has high mobility, penetrates the interlayer insulating film, reaches the TFT, contaminates the channel layer, and degrades the TFT performance.
[0035]
Of course, a configuration in which not only Li but also highly mobile Na is contained in the cathode is not preferable for the same reason. The smaller the amount of Li and Na contained in the cathode, the better.
[0036]
Moreover, it turned out that it is preferable to use the electrode containing Mg with low diffusibility for a cathode. For example, it is very effective to use AlMg or MgAg.
[0037]
In addition, the organic compound layer included in the light-emitting element of the present invention can be formed using a known organic compound material, but also includes those formed by including an inorganic material in a part thereof. For example, by using an alkali metal element or alkaline earth metal element having a low work function and using a layer containing these as part of the organic compound layer, it is possible to improve the electron injectability from the cathode. In addition, a light-emitting element having excellent characteristics can also be formed by including an inorganic material that can enhance the transportability of injected carriers in part. In the present invention, the types of inorganic materials contained in the organic compound layer and the arrangement of the layers containing these in the organic compound layer are not particularly limited, and known inorganic materials can be used in a free arrangement. Can do.
[0038]
Note that the present invention can be used not only for an active matrix light-emitting device but also for a passive light-emitting device.
[0039]
The configuration of the present invention is shown below.
[0040]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode has a content of Li or Na, respectively. 1 × 10 ¹⁸ atoms / cm ^Three There is provided a method for repairing a light emitting device, wherein a reverse bias voltage is applied between the anode and the cathode.
[0041]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode has a Li or Na content of 1 each. × 10 ¹⁸ atoms / cm ^Three By applying a reverse bias voltage between the anode and the cathode, a current is caused to flow through the portion where the anode and the cathode are electrically short-circuited, and the short-circuited portion is heated, Provided is a method for repairing a light-emitting device, characterized in that a heated portion is increased in resistance or insulation.
[0042]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode has a content of Li or Na, respectively. 1 × 10 ¹⁸ atoms / cm ^Three The organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, and a reverse bias voltage between the anode and the cathode. Is applied to cause a current to flow in a portion where the upper layer of the light emitting layer and a lower layer of the light emitting layer are electrically short-circuited to generate heat in the short-circuited portion, and the heated portion is increased. Provided is a method for repairing a light-emitting device, which is characterized by being made resistive or insulating.
[0043]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode has a content of Li or Na, respectively. 1 × 10 ¹⁸ atoms / cm ^Three By applying a reverse bias voltage between the anode and the cathode, at least one of the anode or the cathode is inserted into the organic compound layer, and the anode and the cathode are electrically connected to each other. Provided is a method for repairing a light emitting device, characterized in that a current is passed through the contacted portion.
[0044]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the current is passed through a portion where the anode and the cathode are in electrical contact to generate heat, and the heated portion is increased in resistance or insulation. Is done.
[0045]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode has a content of Li or Na, respectively. 1 × 10 ¹⁸ atoms / cm ^Three The organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light emitting layer, and a reverse bias voltage between the anode and the cathode. Is applied, either the layer above the light emitting layer or the layer below the light emitting layer enters the light emitting layer, and the layer above the light emitting layer and the layer below the light emitting layer are Provided is a method for repairing a light emitting device, characterized in that a current is passed through a portion in electrical contact.
[0046]
According to the present invention, the current is passed through a portion where the upper layer of the light emitting layer and the lower layer of the light emitting layer are in electrical contact to generate heat, and the heated portion is increased in resistance or insulation. A featured light emitting device repair method is provided.
[0047]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the cathode is an alloy containing at least one of Be, Mg, Ca, Sr, and Ba.
[0048]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the cathode is an alloy containing magnesium.
[0049]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the cathode is AlMg, MgAg, or MgAgAl.
[0050]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least one of Al or Ag; There is provided a method for repairing a light-emitting device, which is an alloy containing Mg and applying a reverse bias voltage between the anode and the cathode.
[0051]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least one of Al or Ag; Mg is an alloy, and by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited, and the short-circuited portion is There is provided a method for repairing a light emitting device, characterized in that heat is generated and the heated portion is increased in resistance or insulation.
[0052]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least one of Al or Ag; Mg is an alloy, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light-emitting layer, and is provided between the anode and the cathode. By applying a reverse bias voltage, a current is passed through a portion where the upper layer of the light emitting layer and a lower layer of the light emitting layer are electrically short-circuited to generate heat in the short-circuited portion, and the heat generation There is provided a method for repairing a light emitting device, characterized by increasing the resistance or insulation of the portion.
[0053]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least one of Al or Ag; Mg is an alloy, and by applying a reverse bias voltage between the anode and the cathode, at least one of the anode or the cathode is intruded into the organic compound layer, and the anode and the cathode There is provided a method for repairing a light emitting device, characterized in that a current is passed through a portion where the electrodes are in electrical contact.
[0054]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the current is passed through a portion where the anode and the cathode are in electrical contact to generate heat, and the heated portion is increased in resistance or insulation. Is done.
[0055]
According to the present invention, there is provided a method for repairing a light emitting device including an organic light emitting device having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein the cathode is at least one of Al or Ag; Mg is an alloy, and the organic compound layer has a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, and a light-emitting layer, and is provided between the anode and the cathode. By applying a reverse bias voltage, either the upper layer of the light emitting layer or the lower layer of the light emitting layer enters the light emitting layer, and the upper layer of the light emitting layer and the lower layer of the light emitting layer are inserted. A method of repairing a light emitting device is provided, in which a current is passed through a portion in electrical contact with the layer.
[0056]
According to the present invention, the current is passed through a portion where the upper layer of the light emitting layer and the lower layer of the light emitting layer are in electrical contact to generate heat, and the heated portion is increased in resistance or insulation. A featured light emitting device repair method is provided.
[0057]
According to the invention, the cathode has a Li or Na content of 1 × 10 respectively. ¹⁸ atoms / cm ^Three A method for repairing a light emitting device is provided which is characterized by the following.
[0058]
According to the invention, the cathode has a Mg content of 1 × 10 ²⁰ atoms / cm ^Three The repair method of the light-emitting device characterized by the above is provided.
[0059]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the reverse bias voltage is applied at regular intervals.
[0060]
According to the present invention, when the reverse bias voltage is applied, the light emitting device is gradually increased until it falls within ± 15% of the height at which an avalanche current starts to flow in the organic compound layer. Is provided.
[0061]
According to the present invention, there is provided a method for repairing a light emitting device, wherein the organic light emitting elements are arranged in a matrix and have thin film transistors connected to the organic light emitting elements.
[0062]
According to the present invention, there is provided a method for manufacturing a light-emitting device including an organic light-emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, each having a Li or Na content of 1 × 10 ¹⁸ atoms / cm ^Three There is provided a method for manufacturing a light-emitting device, wherein after forming a cathode as described below, a reverse bias voltage is applied between the anode and the cathode.
[0063]
According to the present invention, there is provided a method for manufacturing a light-emitting device including an organic light-emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, each having a Li or Na content of 1 × 10 ¹⁸ atoms / cm ^Three After forming a cathode that is the following, by applying a reverse bias voltage between the anode and the cathode, a current is caused to flow in a portion where the anode and the cathode are electrically short-circuited, and the short-circuited portion A method for manufacturing a light-emitting device is provided, in which the heat-generating portion is increased in resistance or insulation.
[0064]
According to the present invention, there is provided a method of manufacturing a light-emitting device including an organic light-emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al or Ag and Mg There is provided a method for manufacturing a light-emitting device, characterized in that a reverse bias voltage is applied between the anode and the cathode after forming a cathode made of an alloy containing the cathode.
[0065]
According to the present invention, there is provided a method of manufacturing a light-emitting device including an organic light-emitting element having an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode, wherein at least one of Al or Ag and Mg After forming a cathode made of an alloy containing,
By applying a reverse bias voltage between the anode and the cathode, a current is caused to flow through the portion where the anode and the cathode are electrically short-circuited, the short-circuited portion is heated, and the heated portion is A method for manufacturing a light-emitting device, characterized by increasing resistance or insulation.
[0066]
DETAILED DESCRIPTION OF THE INVENTION
The repair method of the present invention will be described with reference to FIG. FIG. 1A is a diagram schematically showing a current flow when a reverse bias voltage is applied to an organic light emitting device having a defect.
[0067]
The organic light emitting device has a ground voltage GND and a reverse bias voltage V. _rev Are applied alternately. FIG. 1B shows the voltage V of the reverse bias and the ground voltage GND. _rev The timing chart when is applied alternately is shown. In this embodiment, ground voltage GND and reverse bias voltage V _rev However, the present invention is not limited to this configuration. In the present invention, a reverse bias current may flow in the organic light emitting element. Therefore, forward bias voltage and reverse bias voltage V _rev May be alternately applied to the organic light emitting device.
[0068]
Further, in the present embodiment, a reverse bias voltage is applied to the organic light emitting element at regular intervals, but the present invention is not limited to this. A direct reverse bias voltage may be applied to the organic light emitting device.
[0069]
In the present embodiment, the reverse bias voltage is gradually increased until an avalanche phenomenon occurs and an avalanche current flows through the organic light emitting element. In the present specification, a voltage at which an avalanche current starts to flow in the organic light emitting element is referred to as an avalanche voltage. However, the present invention is not limited to this configuration, and the voltage applied to the organic light emitting element can be appropriately set by the designer. The voltage applied to the organic light-emitting element may be high enough to denature the defective portion and high enough not to break the organic light-emitting element or deteriorate the organic compound layer.
[0070]
Further, the reverse bias voltage applied with direct current may be gradually increased.
[0071]
Furthermore, a reverse bias voltage having a constant height may be applied to the organic light emitting element at regular intervals, or may be applied with a direct current.
[0072]
When a reverse bias voltage is applied to the organic light emitting element at regular intervals, it is possible to prevent the organic compound layer around the defect portion from being deteriorated by heat generated by the application of the reverse bias voltage.
[0073]
Further, by gradually increasing the reverse bias voltage, it becomes easy to find the optimum reverse bias voltage for the organic light emitting device to be repaired.
[0074]
Reverse bias voltage V for organic light emitting devices _rev Is applied to the organic light emitting device, the reverse bias current I _rev Flows. Reverse bias current I _rev Is the current flowing through the organic compound layer 103 I _dio , The current flowing through the defect 104 _SC Then I _rev = I _dio + I _SC Meet. However, since the reverse bias current hardly flows through the organic compound layer, I _rev ≒ I _SC Holds.
[0075]
Current I _rev When the liquid flows into the defect portion 104, the temperature of the defect portion 104 increases, so that the defect portion is burnt out, vaporizes and evaporates, or is oxidized or carbonized to become an insulator to become a modified layer. . Therefore, resistance R _SC Becomes larger.
[0076]
FIG. 2A shows a change in voltage-current characteristics of an organic light emitting element having a defect 104 over time when the repair method of the present invention is used. The graph of the voltage-current characteristic changes in the direction of the arrow with time. V _av Means an avalanche voltage. Since the current flowing through the organic light emitting element when the reverse bias voltage is applied as time passes, the resistance R of the defective portion is reduced. _SC And the current I flowing through the defect is increased accordingly. _SC Becomes smaller.
[0077]
FIG. 2B schematically shows a current flow when a forward bias voltage is applied to the organic light emitting element. Current I flowing through the defect _SC Becomes smaller, the current I actually flowing in the organic compound layer when a forward bias voltage is applied to the organic light emitting element is reduced. _dio Becomes larger and the light emission luminance becomes higher.
[0078]
The organic light emitting device has a configuration in which an organic compound layer is sandwiched between an anode and a cathode. A well-known material may be freely used for the anode and the organic compound layer. However, in the present invention, care must be taken so that a highly mobile component such as Na or Li does not enter the cathode. The content of Li and Na is 1 × 10 ¹⁸ atoms / cm ^Three If the value exceeds 1, Li and Na diffuse from the cathode and affect the TFT performance, and the TFT characteristics deteriorate or become unstable. Therefore, the contents of Na and Li are both 1 × 10 ¹⁸ atoms / cm ^Three It is necessary to do the following.
[0079]
In the present invention, an alloy containing magnesium having a low work function is used for the cathode. For example, AlMg or MgAg is preferably used. The amount of Mg contained in the cathode can be freely determined in consideration of the work function of the cathode. However, the amount of Mg contained is 1 × 10 ²⁰ atoms / cm ² If it is less than this, the work function becomes high and the light emission efficiency decreases. Therefore, the amount of Mg contained in the cathode is at least 1 × 10 ²⁰ atoms / cm ² The above is preferable.
[0080]
By using the method of the present invention, pinholes are formed due to the influence of dust or the like during the formation of the organic compound layer, and even if the two layers formed with the light emitting layer in between are short-circuited, they are short-circuited. The resistance can be increased by changing the defective portion to the modified portion, and the current that actually flows through the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting device. Therefore, the repairing method of the present invention can increase the light emission luminance when the same voltage is applied even if a defect exists.
[0081]
In addition, since a current always flows in the defect portion, the deterioration of the organic compound layer existing around the defect portion is easily promoted. However, the modified layer has a resistance R _SC Therefore, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer.
[0082]
Further, since the cathode of the organic light emitting element is mainly composed of Mg, Al, and Ag having low diffusibility, it becomes possible to prevent contamination of the device due to application of a reverse bias.
[0083]
【Example】
Examples of the present invention will be described below.
[0084]
Example 1
In this embodiment, an example in which the repair method of the present invention is used for an active matrix light-emitting device having two thin film transistors (TFTs) in each pixel will be described.
[0085]
FIG. 3 is a circuit diagram of a pixel of a light emitting device using the repair method of the present invention. Each pixel includes a source signal line Si (i is any one of 1 to x), a power supply line Vi (i is any one of 1 to x), and a gate signal line Gj (j is 1 to y). Any one).
[0086]
Each pixel has a switching TFT 301, a driving TFT 302, an organic light emitting element 303, and a capacitor 304.
[0087]
The gate electrode of the switching TFT 301 is connected to the gate signal line Gi. One of the source region and the drain region of the switching TFT 301 is connected to the source signal line Si, and the other is connected to the gate electrode of the driving TFT 302.
[0088]
The source region of the driving TFT 302 is connected to the power supply line Vi, and the drain region is connected to one of the two electrodes of the organic light emitting element 303. Of the two electrodes of the organic light emitting element 303, the one not connected to the drain region of the driving TFT 302 is connected to the counter power supply 307.
[0089]
Of the two electrodes of the organic light emitting element 303, the electrode connected to the drain region of the driving TFT 302 is called a pixel electrode, and the electrode connected to the counter power source 307 is called a counter electrode.
[0090]
The capacitor 304 is formed between the gate electrode of the driving TFT 302 and the power supply line Vi.
[0091]
FIG. 4A illustrates a pixel portion of a light-emitting device including a plurality of pixels illustrated in FIG. The pixel portion 306 includes source signal lines S1 to Sx, power supply lines V1 to Vx, and gate signal lines G1 to Gy. A plurality of pixels 305 are formed in a matrix in the pixel portion 306.
[0092]
FIG. 4B shows the operation of the TFT in each pixel and the level of the voltage input to the power supply line Vi and the counter electrode when repairing the defective portion of the organic light emitting element 303. When repairing the defective portion of the organic light emitting element 303, both the switching TFT 301 and the driving TFT 302 of each pixel are turned on. Then, the voltage of the power supply line Vi is made constant, and the voltage of the counter electrode is changed every fixed period, so that a predetermined reverse bias current flows through the organic light emitting element every fixed period.
[0093]
The repair of the defect of the organic light emitting element may be performed simultaneously for all the pixels 305 included in the pixel portion 306, or may be performed for each line or each pixel.
[0094]
In this embodiment, of the two electrodes of the organic light emitting device, the cathode is formed using an alloy containing magnesium, such as AlMg or MgAg. The cathode is prevented from mixing highly mobile components such as Na and Li, and the contents of these Na and Li are all 1 × 10. ¹⁸ atoms / cm ² The following.
[0095]
According to the circuit of this embodiment, a reverse bias can be applied to the organic light emitting element by appropriately adjusting the voltage applied to the switching TFT, the driving TFT, the power supply line, and the counter power supply. Since the cathode of the organic light emitting element is strictly controlled so that Li and Na are not included, it is possible to apply a reverse bias without contaminating the device.
[0096]
(Example 2)
In this embodiment, an example in which the repair method of the present invention is used for an active matrix light-emitting device having three thin film transistors (TFTs) in each pixel will be described.
[0097]
FIG. 5 shows a circuit diagram of a pixel of a light emitting device using the repair method of the present invention. Each pixel includes a source signal line Si (i is any one of 1 to x), a power supply line Vi (i is any one of 1 to x), and a write gate signal line Gaj (j is 1 to 1). any one of y) and an erasing gate signal line Gej (j is any one of 1 to y).
[0098]
Each pixel includes a switching TFT 501a, an erasing TFT 501b, a driving TFT 502, an organic light emitting element 503, and a capacitor 504.
[0099]
The gate electrode of the switching TFT 501a is connected to the write gate signal line Gaj. One of the source region and the drain region of the switching TFT 501 a is connected to the source signal line Si, and the other is connected to the gate electrode of the driving TFT 502.
[0100]
The gate electrode of the erasing TFT 501b is connected to the erasing gate signal line Gej. One of the source region and the drain region of the erasing TFT 501 b is connected to the power supply line Vi, and the other is connected to the gate electrode of the driving TFT 502.
[0101]
The source region of the driving TFT 502 is connected to the power supply line Vi, and the drain region is connected to one of the two electrodes of the organic light emitting element 503. Of the two electrodes of the organic light emitting element 503, the one not connected to the drain region of the driving TFT 502 is connected to the counter power source 507.
[0102]
Of the two electrodes of the organic light emitting element 503, the electrode connected to the drain region of the driving TFT 502 is referred to as a pixel electrode, and the electrode connected to the counter power source 507 is referred to as a counter power source.
[0103]
The capacitor 504 is formed between the gate electrode of the driving TFT 502 and the power supply line Vi.
[0104]
FIG. 6A illustrates a pixel portion of a light-emitting device including a plurality of pixels illustrated in FIG. The pixel portion 506 includes source signal lines S1 to Sx, power supply lines V1 to Vx, write gate signal lines Ga1 to Gay, and erase gate signal lines Ge1 to Gey. In the pixel portion 506, a plurality of pixels 505 are formed in a matrix.
[0105]
FIG. 6B shows the operation of the TFT in each pixel and the level of the voltage input to the power supply line Vi and the counter electrode when repairing the defective portion of the organic light emitting element 503. When repairing the defective portion of the organic light emitting element 503, both the switching TFT 501a and the driving TFT 502 of each pixel are turned on. Further, the erasing TFT 501b of each pixel is turned off. Then, the voltage of the power supply line Vi is made constant, and the voltage of the counter electrode is changed every fixed period, so that a predetermined reverse bias current flows through the organic light emitting element 503 every fixed period.
[0106]
The defect repair of the organic light emitting element 503 may be performed simultaneously for all the pixels 505 included in the pixel portion 506, or may be performed for each line or each pixel.
[0107]
Note that the cathode of the organic light emitting element is formed using an alloy containing magnesium, such as AlMg or MgAg, so that alkali is not eluted when a reverse bias is applied. The cathode is strictly controlled so that highly mobile components such as Na and Li are not mixed. The contents of Na and Li are both 1 × 10. ¹⁸ atoms / cm ² The following.
[0108]
Even in the circuit of the present embodiment, it is possible to apply a reverse bias to the organic light emitting element.
[0109]
(Example 3)
In this embodiment, an example in which the repair method of the present invention is used for an active matrix light-emitting device having three thin film transistors (TFTs) in each pixel will be described.
[0110]
FIG. 7 shows a circuit diagram of a pixel of a light emitting device using the repair method of the present invention. Each pixel includes a source signal line Si (i is any one of 1 to x), a power supply line Vi (i is any one of 1 to x), and a gate signal line Gj (j is 1 to y). Any one).
[0111]
Each pixel includes a switching TFT 401, a driving TFT 402, an organic light emitting element 403, a capacitor 404, and a reverse bias applying TFT 408.
[0112]
The gate electrode of the switching TFT 401 is connected to the gate signal line Gi. One of the source region and the drain region of the switching TFT 401 is connected to the source signal line Si, and the other is connected to the gate electrode of the driving TFT 402.
[0113]
The source region of the driving TFT 402 is connected to the power supply line Vi, and the drain region is connected to one of the two electrodes of the organic light emitting element 403. Of the two electrodes of the organic light emitting element 403, the one not connected to the drain region of the driving TFT 402 is connected to the counter power source 407.
[0114]
Of the two electrodes of the organic light emitting element 403, the electrode connected to the drain region of the driving TFT 402 is called a pixel electrode, and the electrode connected to the counter power source 407 is called a counter electrode.
[0115]
The gate electrode of the reverse bias applying TFT 408 is connected to the power supply line Vi. One of the source region and the drain region of the reverse bias applying TFT 408 is connected to the power supply line Vi, and the other is connected to the pixel electrode of the organic light emitting element.
[0116]
The capacitor 404 is formed between the gate electrode of the driving TFT 402 and the power supply line Vi.
[0117]
FIG. 8A illustrates a pixel portion of a light-emitting device including a plurality of pixels illustrated in FIG. The pixel portion 406 includes source signal lines S1 to Sx, power supply lines V1 to Vx, and gate signal lines G1 to Gy. In the pixel portion 406, a plurality of pixels 405 are formed in a matrix.
[0118]
FIG. 8B shows the operation of the TFT in each pixel and the level of the voltage input to the power supply line Vi and the counter electrode when repairing the defective portion of the organic light emitting element 403. When the defective portion of the organic light emitting element 403 is repaired, both the switching TFT 401 and the driving TFT 402 of each pixel are turned off. Then, the reverse bias applying TFT 408 having the rectifying characteristic is turned on and a voltage is applied in the forward direction. Then, a current flows through the reverse bias TFT, and a reverse bias is applied to the organic light emitting element. By making the voltage of the power supply line Vi constant and changing the voltage of the counter electrode every fixed period, a current having a predetermined reverse bias is supplied to the organic light emitting element every fixed period.
[0119]
The repair of the defect of the organic light emitting element may be performed simultaneously for all the pixels, or may be performed for each line.
[0120]
Note that the cathode of the organic light emitting element is formed using an alloy containing magnesium, such as AlMg or MgAg, so that alkali is not eluted when a reverse bias is applied. The cathode is strictly controlled so that highly mobile components such as Na and Li are not mixed. The contents of Na and Li are both 1 × 10. ¹⁸ atoms / cm ² The following.
[0121]
The circuit of this embodiment can easily reverse bias the organic light-emitting element simply by adjusting the potential of the power supply line and the potential of the counter power source.
[0122]
Example 4
In this example, a case where the repair method of the present invention is used for an organic light-emitting element in which an organic compound layer is formed of a plurality of layers will be described.
[0123]
FIG. 9A shows a structure of the organic light emitting element. First, PEDOT, which is a polythiophene derivative, is formed with a film thickness of 30 nm as a hole injection layer on an anode made of a compound (ITO) in which indium oxide and tin oxide are combined. Next, 20 nm of MTDATA and 10 nm of α-NPD are formed as a hole transport layer by a vapor deposition method. Alq which is a singlet compound as a light emitting material for forming a light emitting layer thereon _Three Is deposited to a thickness of 50 nm by vapor deposition. And an organic light emitting element is formed by vapor-depositing AlMg to a film thickness of 100 nm as a cathode.
[0124]
In the light emitting layer of the organic light emitting device having the above configuration, when a defect portion due to a pinhole is formed, AlMg as a cathode comes into contact with α-NPD as a hole transport layer in the defect portion.
[0125]
By supplying a reverse bias current to the organic light emitting device having the defective portion at regular intervals, the temperature of the defective portion rises, the defective portion is burned out, evaporated and evaporated, or oxidized or carbonized to be insulated. As a result, the defective part is changed to a denatured part, and the resistance can be increased. Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.
[0126]
In addition, light emission obtained by this organic light-emitting element utilizes singlet excitation energy by a singlet compound.
[0127]
FIG. 9B shows the structure of another organic light emitting element. First, copper phthalocyanine is formed in a thickness of 20 nm as a hole injection layer on a positive electrode made of a combination of indium oxide and tin oxide by a vapor deposition method. Next, α-NPD was formed to a thickness of 10 nm by a vapor deposition method as a hole transport layer. Ir (ppy) which is a triplet compound as a light emitting material for forming a light emitting layer thereon _Three And CBP are deposited to a thickness of 20 nm by vapor deposition. Furthermore, 10 nm of BCP as an electron transport layer on the light emitting layer, Alq _Three Are formed by vapor deposition, and then AlMg is deposited as a cathode to a thickness of 100 nm to form an organic light emitting device.
[0128]
In the light emitting layer of the organic light emitting element having the above configuration, when a defect portion due to pinholes is formed, BCP which is an electron transport layer contacts the α-NPD which is a hole transport layer in the defect portion.
[0129]
By supplying a reverse bias current to the organic light emitting device having the defective portion at regular intervals, the temperature of the defective portion rises, the defective portion is burned out, evaporated and evaporated, or oxidized or carbonized to be insulated. As a result, the defective portion is changed to a denatured portion, and the resistance can be increased. Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.
[0130]
In addition, light emission obtained by this organic light-emitting element utilizes triplet excitation energy by the triplet compound.
[0131]
FIG. 10A shows the structure of the organic light emitting element. First, PEDOT, which is a polythiophene derivative, is formed in a film thickness of 30 nm as a hole injection layer on an anode made of a compound (ITO) that is a combination of indium oxide and tin oxide. Alq which is a singlet compound as a light emitting material for forming a light emitting layer thereon _Three Is deposited to a thickness of 50 nm by vapor deposition. And an organic light emitting element is formed by vapor-depositing AlMg to a film thickness of 100 nm as a cathode.
[0132]
In the light emitting layer of the organic light emitting device having the above configuration, when a defect portion due to a pinhole is formed, AlMg as a cathode comes into contact with PEDOT as a hole injection layer in the defect portion.
[0133]
By supplying a reverse bias current to the organic light emitting device having the defective portion at regular intervals, the temperature of the defective portion rises, the defective portion is burned out, evaporated and evaporated, or oxidized or carbonized to be insulated. As a result, the defective part is changed to a denatured part, and the resistance can be increased. Therefore, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer from being promoted.
[0134]
In addition, light emission obtained by this organic light-emitting element utilizes singlet excitation energy by a singlet compound.
[0135]
FIG. 10B shows a structure of the organic light emitting element. First, AlMg is deposited to a thickness of 100 nm as a cathode. Alq which is a singlet compound as a light emitting material for forming a light emitting layer thereon _Three Is deposited to a thickness of 50 nm by vapor deposition. Next, as a hole injection layer, PEDOT, which is a polythiophene derivative, is formed with a film thickness of 30 nm by spin coating. Then, Au is deposited with a film thickness of 5 nm. Note that Au is provided in order to prevent the surface of the organic compound layer from deteriorating in a later step. An organic light-emitting device is formed by forming an anode made of a compound (ITO) in which indium oxide and tin oxide are combined on it.
[0136]
In the light emitting layer of the organic light emitting device having the above configuration, when a defect portion due to a pinhole is formed, AlMg as a cathode comes into contact with PEDOT as a hole injection layer in the defect portion.
[0137]
In addition, light emission obtained by this organic light-emitting element utilizes singlet excitation energy by a singlet compound.
[0138]
In the present invention, a pinhole is formed due to the influence of dust or the like during the formation of the organic compound layer, and even if the two layers formed with the light emitting layer in between are short-circuited, the defective portion is short-circuited. By increasing the resistance, it is possible to increase the current that actually flows through the organic compound layer when a forward bias voltage is applied to the organic light emitting device. Therefore, the repairing method of the present invention can increase the light emission luminance when the same voltage is applied even if a defect exists.
[0139]
Further, by increasing the resistance by changing the defective portion to the modified portion, it is possible to prevent the deterioration of the organic compound layer existing around the modified layer.
[0140]
Note that a carbide formed by carbonizing the material of the light-emitting element has high insulating properties and is stable as a substance. Therefore, in the case where an organic compound material is further stacked in the defect portion, for example, as shown in FIG. _Three ) In the light emitting layer (Alq _Three The repair method of the present invention is particularly effective when a hole injection layer (PEDOT) is formed in contact with the layer.
[0141]
Note that this embodiment can be implemented by being freely combined with Embodiments 1 to 3.
[0142]
(Example 5)
In the light-emitting device using the repair method of the present invention, a material of a light-emitting element that can use phosphorescence from triplet excitons for light emission can be used. A light-emitting device using a material of a light-emitting element that can use phosphorescence for light emission can dramatically improve external light emission quantum efficiency. This makes it possible to reduce the power consumption, extend the life, and reduce the weight of the organic light emitting device.
[0143]
Here, a report of using triplet excitons to improve the external emission quantum efficiency is shown.
(T. Tsutsui, C. Adachi, S. Saito, Photochemical Processes in Organized Molecular Systems, ed. K. Honda, (Elsevier Sci. Pub., Tokyo, 1991) p.437.)
[0144]
The molecular formula of the light emitting device material (coumarin dye) reported by the above paper is shown below.
[0145]
[Chemical 1]

[0146]
(MABaldo, DFO'Brien, Y.You, A.Shoustikov, S.Sibley, METhompson, SRForrest, Nature 395 (1998) p.151.)
[0147]
The molecular formula of the light emitting device material (Pt complex) reported by the above paper is shown below.
[0148]
[Chemical 2]

[0149]
(MABaldo, S. Lamansky, PEBurrrows, METhompson, SRForrest, Appl.Phys.Lett., 75 (1999) p.4.) (T.Tsutsui, M.-J.Yang, M.Yahiro, K.Nakamura, T Watanabe, T.tsuji, Y.Fukuda, T.Wakimoto, S.Mayaguchi, Jpn.Appl.Phys., 38 (12B) (1999) L1502.)
[0150]
The molecular formula of the light emitting device material (Ir complex) reported by the above paper is shown below.
[0151]
[Chemical 3]

[0152]
As described above, if phosphorescence emission from triplet excitons can be used, in principle, it is possible to realize an external emission quantum efficiency that is 3 to 4 times higher than that in the case of using fluorescence emission from singlet excitons.
[0153]
In addition, the structure of a present Example can be implemented in combination with any structure of Example 1- Example 4 freely.
[0154]
(Example 6)
In this example, a cross-sectional view of a light emitting device using the repair method of the present invention will be described.
[0155]
In FIG. 14, a switching TFT 721 provided over a substrate 700 is formed using an n-channel TFT 503.
[0156]
In this embodiment, the switching TFT 721 has a double gate structure in which two channel forming regions are formed. However, the switching TFT 721 has a single gate structure in which one channel forming region is formed or a triple gate structure in which three channel forming regions are formed. Also good.
[0157]
A driver circuit provided over the substrate 700 includes an n-channel TFT 723 and a p-channel TFT 724. In this embodiment, the TFT included in the driver circuit has a single gate structure, but may have a double gate structure or a triple gate structure.
[0158]
Further, the wirings 701 and 703 function as source wirings of the CMOS circuit, and the wiring 702 functions as a drain wiring. Further, the wiring 704 functions as a wiring that electrically connects the source wiring 708 and the source region of the switching TFT, and the wiring 705 functions as a wiring that electrically connects the drain wiring 709 and the drain region of the switching TFT. To do.
[0159]
Note that the driving TFT 722 is formed using a p-channel TFT. In this embodiment, the driving TFT 722 has a single gate structure, but may have a double gate structure or a triple gate structure.
[0160]
A wiring 706 is a source wiring (corresponding to a current supply line) of a driving TFT, and an electrode 707 is an electrode electrically connected to the pixel electrode 710 by being superimposed on the pixel electrode 710 of the driving TFT.
[0161]
Reference numeral 710 denotes a pixel electrode (an anode of an organic light emitting element) made of a transparent conductive film. As the transparent conductive film, a compound of indium oxide and tin oxide, a compound of indium oxide and zinc oxide, zinc oxide, tin oxide, or indium oxide can be used. Moreover, you may use what added the gallium to the said transparent conductive film. The pixel electrode 710 is formed on the flat interlayer insulating film 711 before forming the wiring. In this embodiment, it is very important to flatten the step due to the TFT using the flattening film 711 made of resin. Since an organic compound layer formed later is very thin, a light emission defect may occur due to the presence of a step. Therefore, it is desirable that the organic compound layer be flattened before forming the pixel electrode so that the organic compound layer can be formed as flat as possible.
[0162]
After the wirings 701 to 707 are formed, a bank 712 is formed as shown in FIG. The bank 712 may be formed by patterning an insulating film or organic resin film containing silicon of 100 to 400 nm.
[0163]
An organic compound layer 713 is formed on the pixel electrode 710. Although only one pixel is shown in FIG. 14, organic compound layers corresponding to each color of R (red), G (green), and B (blue) are separately formed in this embodiment. In this embodiment, the low molecular weight organic compound layer is formed by vapor deposition. Specifically, a copper phthalocyanine (CuPc) film having a thickness of 20 nm is provided as the hole injection layer 713a, and a tris-8-quinolinolato aluminum complex (Alq) having a thickness of 70 nm is formed thereon as the light emitting layer 713b. _Three ) A laminated structure provided with a film. Alq _Three The emission color can be controlled by adding a fluorescent dye such as quinacridone, perylene, or DCM1.
[0164]
However, the above example is an example of an organic compound material that can be used as the organic compound layer, and is not necessarily limited to this. A light emitting layer, a charge transport layer, or a charge injection layer may be freely combined to form an organic compound layer (a layer for causing light emission and carrier movement therefor). For example, in this embodiment, an example in which a low molecular weight organic compound material is used as the organic compound layer is shown, but a high molecular weight organic compound material may be used. It is also possible to use an inorganic material such as silicon carbide for the charge transport layer or the charge injection layer. As these organic materials and inorganic materials, known materials can be used.
[0165]
Next, a cathode 714 made of a conductive film is provided on the organic compound layer 713. In this embodiment, an alloy film of aluminum and magnesium is used as the conductive film. Of course, a known MgAg film (magnesium and silver alloy film) may be used. As the cathode material, a conductive film made of an element belonging to Group 2 of the periodic table or a conductive film added with these elements may be used. For example, at least one of Be, Mg, Ca, Sr, and Ba is added.
[0166]
Note that when the cathode has a structure in which two layers of films are stacked, magnesium is formed in contact with the organic compound layer, and aluminum is formed on the magnesium, the voltage at which the organic light emitting element starts to emit light can be reduced. . At this time, magnesium is preferably 10 nm thick and aluminum is preferably 100 nm thick.
[0167]
When the cathode 714 is formed, the organic light emitting device 719 is completed. Note that the organic light-emitting element 719 here refers to a capacitor formed by a pixel electrode (anode) 710, an organic compound layer 713, and a cathode 714.
[0168]
It is effective to provide a passivation film 716 so as to completely cover the organic light emitting element 719. As the passivation film 716, an insulating film including a carbon film, a silicon nitride film, or a silicon nitride oxide film is used, and the insulating film is used as a single layer or a combination thereof.
[0169]
At this time, it is preferable to use a film with good coverage as the passivation film, and it is effective to use a carbon film, particularly a DLC (diamond-like carbon) film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C., it can be easily formed over the organic compound layer 713 having low heat resistance. In addition, the DLC film has a high blocking effect against oxygen and can suppress oxidation of the organic compound layer 713. Therefore, the problem that the organic compound layer 713 is oxidized during the subsequent sealing process can be prevented.
[0170]
Further, a sealing material 717 is provided over the passivation film 716 and a cover material 718 is attached thereto. As the sealing material 717, an ultraviolet curable resin may be used, and it is effective to provide a substance having a moisture absorption effect or a substance having an antioxidant effect inside. In this embodiment, the cover material 718 is formed by forming a carbon film (preferably a diamond-like carbon film) on both surfaces of a glass substrate, a quartz substrate, or a plastic substrate (including a plastic film).
[0171]
Thus, a light emitting device having a structure as shown in FIG. 14 is completed. Note that it is effective to continuously process the steps from the formation of the bank 712 to the formation of the passivation film 716 using a multi-chamber type (or in-line type) film formation apparatus without releasing to the atmosphere. . Further, it is possible to continuously process the process up to the step of bonding the cover material 718 without releasing to the atmosphere.
[0172]
Further, the TFT in this embodiment is characterized in that the gate electrode is formed of a two-layer conductive film, and there is almost no difference in concentration in the low concentration impurity region provided between the channel formation region and the drain region. It has a gentle concentration gradient and includes a region (GOLD region) that overlaps with the lower gate electrode and a region (LDD region) that does not overlap with the gate electrode. Further, the peripheral portion of the gate insulating film, that is, the region not overlapping with the gate electrode and the region above the high concentration impurity region are tapered.
[0173]
In the light emitting device of this embodiment, when a pinhole is formed in the light emitting layer 713b, a defective portion in which the hole injection layer 713a and the cathode 714 are in contact with each other through the pinhole is formed. The resistance can be increased by changing the defective portion to the modified portion 715 by the repair method of the present invention. Therefore, it is possible to increase the luminance of portions other than the pinhole of the pixel and prevent the deterioration of the organic compound layer around the pinhole.
[0174]
In addition, in this embodiment, only the configuration of the pixel portion and the drive circuit is shown. However, according to the manufacturing process of this embodiment, other logic circuits such as a signal dividing circuit, a D / A converter, an operational amplifier, and a γ correction circuit are provided. Can be formed on the same insulator, and a memory or a microprocessor can also be formed.
[0175]
The configuration of the present embodiment can be implemented by freely combining with the first, second, third, or eighth embodiment.
(Example 7)
In this example, a cross-sectional view of a light emitting device using the repair method of the present invention will be described.
[0176]
In FIG. 15, a p-channel TFT 200, an n-channel TFT 201, a driving TFT 203, a switching TFT 204, and a storage capacitor of a pixel portion are formed over the same substrate.
[0177]
In the p-channel TFT 200 of the driver circuit, a conductive layer 220 having a second taper shape functions as a gate electrode, and a third impurity region functions as a channel formation region 206, a source region, or a drain region. 207a, a fourth impurity region (A) 207b that forms an LDD region that does not overlap with the gate electrode 220, and a fourth impurity region (B) 207c that forms an LDD region that partially overlaps the gate electrode 220. ing.
[0178]
In the n-channel TFT 201, the conductive layer 221 having a second tapered shape functions as a gate electrode, and includes a channel formation region 208, a first impurity region 209a that functions as a source region or a drain region, a gate The structure includes a second impurity region (A) (A) 209 b that forms an LDD region that does not overlap with the electrode 221, and a second impurity region (B) 209 c that forms an LDD region that partially overlaps with the gate electrode 221. ing. For the channel length of 2 to 7 μm, the length of the portion where the second impurity region (B) 209 c overlaps with the gate electrode 221 is 0.1 to 0.3 μm. The length of Lov is controlled from the thickness of the gate electrode 221 and the angle of the tapered portion. By forming such an LDD region in an n-channel TFT, a high electric field generated in the vicinity of the drain region can be relaxed, hot carrier generation can be prevented, and TFT deterioration can be prevented.
[0179]
Similarly, in the driving TFT 203, the conductive layer 223 having the second tapered shape has a function as a gate electrode, a channel formation region 212, a third impurity region 213a functioning as a source region or a drain region, a gate The structure includes a fourth impurity region (A) 213 b that forms an LDD region that does not overlap with the electrode 223 and a fourth impurity region (B) 213 c that partially forms an LDD region that overlaps with the gate electrode 223.
[0180]
The drive circuit is formed by a logic circuit such as a shift register circuit or a buffer circuit, a sampling circuit formed by an analog switch, or the like. In FIG. 15, the TFTs forming these are shown as a single gate structure in which one gate electrode is provided between a pair of sources and drains, but a multi-gate structure in which a plurality of gate electrodes are provided between a pair of sources and drains There is no problem.
[0181]
The drain region of the driving TFT 203 is connected to the pixel electrode 271 through the wiring 231. An organic compound layer 272 made of a known organic compound material is formed so as to be in contact with the pixel electrode 271, and a cathode 273 is formed so as to be in contact with the organic compound layer 272.
[0182]
In the switching TFT 204, a conductive layer 224 having a second tapered shape has a function as a gate electrode, and channel formation regions 214a and 214b, a first impurity region 215a that functions as a source region or a drain region, 217, a second impurity region (A) 215b that forms an LDD region that does not overlap with the gate electrode 224, and a second impurity region (B) 215c that forms an LDD region that partially overlaps the gate electrode 224. ing. The length of the portion where the second impurity region (B) 213 c overlaps with the gate electrode 224 is 0.1 to 0.3 μm. In addition, the semiconductor includes a second impurity region (A) 219b, a second impurity region (B) 219c, and a region 218 to which an impurity element that determines a conductivity type is not added, which extends from the first impurity region 217. A storage capacitor is formed from a layer, an insulating layer formed in the same layer as the gate insulating film having a third shape, and a capacitor wiring 225 formed from a conductive layer having a second tapered shape.
[0183]
In the light emitting device of this embodiment, when a pinhole is formed in the organic compound layer 272, a defective portion in which the pixel electrode 271 and the cathode 273 are in contact with each other through the pinhole is formed. The resistance can be increased by changing the defective portion to the modified portion 274 by the repair method of the present invention. Therefore, it is possible to increase the luminance of portions other than the pinhole of the pixel and prevent the deterioration of the organic compound layer around the pinhole.
[0184]
The configuration of the present embodiment can be implemented by freely combining with the first, second, third, or eighth embodiment.
[0185]
(Example 8)
In this example, a cross-sectional view of a light emitting device using the repair method of the present invention will be described.
[0186]
In FIG. 16, reference numeral 811 denotes a substrate, and 812 denotes an insulating film to be a base (hereinafter referred to as a base film). As the substrate 811, a light-transmitting substrate, typically a glass substrate, a quartz substrate, a glass ceramic substrate, or a crystallized glass substrate can be used. However, it must withstand the maximum processing temperature during the fabrication process.
[0187]
In addition, the base film 812 is particularly effective when a substrate containing mobile ions or a conductive substrate is used, but the base film 812 may not be provided on the quartz substrate. As the base film 812, an insulating film containing silicon may be used. Note that in this specification, an “insulating film containing silicon” specifically refers to silicon such as a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film (SiOxNy: x and y are each represented by an arbitrary integer). On the other hand, it refers to an insulating film containing oxygen or nitrogen at a predetermined ratio.
[0188]
Reference numeral 8201 denotes a switching TFT and 8202 denotes a driving TFT, which are formed of an n-channel TFT and a p-channel TFT, respectively. When the direction of light emitted from the organic compound layer is the lower surface of the substrate (the surface where the TFT and the organic compound layer are not provided), the above structure is preferable. However, the present invention is not limited to this configuration. The switching TFT and the driving TFT may be either an n-channel TFT or a p-channel TFT.
[0189]
The switching TFT 8201 includes a source region 813, a drain region 814, an LDD region 815a to 815d, an isolation region 816, and channel formation regions 817a and 817b, a gate insulating film 818, gate electrodes 819a and 819b, An interlayer insulating film 820, a source signal line 821, and a drain wiring 822 are included. Note that the gate insulating film 818 or the first interlayer insulating film 820 may be common to all TFTs on the substrate, or may be different depending on a circuit or an element.
[0190]
Further, the switching TFT 8201 shown in FIG. 16 has a so-called double gate structure in which the gate electrodes 817a and 817b are electrically connected. Needless to say, not only a double gate structure but also a so-called multi-gate structure (a structure including an active layer having two or more channel formation regions connected in series) such as a triple gate structure may be used.
[0191]
The multi-gate structure is extremely effective in reducing the off-current. If the off-current of the switching TFT is sufficiently reduced, the minimum capacity required by the capacitor connected to the gate electrode of the driving TFT 8202 can be reduced. Can be suppressed. In other words, since the area of the capacitor can be reduced, the multi-gate structure is effective in increasing the effective light emitting area of the organic light emitting device.
[0192]
Further, in the switching TFT 8201, the LDD regions 815a to 815d are provided so as not to overlap with the gate electrodes 819a and 819b with the gate insulating film 818 interposed therebetween. Such a structure is very effective in reducing off current. The length (width) of the LDD regions 815a to 815d may be 0.5 to 3.5 μm, typically 2.0 to 2.5 μm.
[0193]
Note that it is more preferable to provide an offset region (a region formed of a semiconductor layer having the same composition as the channel formation region to which no gate voltage is applied) between the channel formation region and the LDD region in order to reduce off-state current. In the case of a multi-gate structure having two or more gate electrodes, an isolation region 816 (a region to which the same impurity element is added at the same concentration as the source region or the drain region) provided between the channel formation regions is provided. It is effective for reducing the off current.
[0194]
Next, the driving TFT 8202 includes an active layer including a source region 826, a drain region 827, and a channel formation region 829, a gate insulating film 818, a gate electrode 830, a first interlayer insulating film 820, a source signal line 831, and A drain wiring 832 is formed. In this embodiment, the driving TFT 8202 is a p-channel TFT.
[0195]
The drain region 814 of the switching TFT 8201 is connected to the gate 830 of the driving TFT 8202. Although not shown, specifically, the gate electrode 830 of the driving TFT 8202 is electrically connected to the drain region 814 of the switching TFT 8201 through a drain wiring (also referred to as connection wiring) 822. Note that the gate electrode 830 has a single gate structure, but may have a multi-gate structure. A source signal line 831 of the driving TFT 8202 is connected to a power supply line (not shown).
[0196]
The driving TFT 8202 is an element for controlling the amount of current injected into the organic light emitting element, and a relatively large amount of current flows. Therefore, it is preferable to design the channel width (W) to be larger than the channel width of the switching TFT. In addition, it is preferable that the channel length (L) be designed to be long so that excessive current does not flow through the driving TFT 8202. Desirably, it is set to 0.5 to 2 μA (preferably 1 to 1.5 μA) per pixel.
[0197]
Furthermore, the deterioration of the TFT may be suppressed by increasing the thickness of the active layer (particularly the channel formation region) of the driving TFT 8202 (preferably 50 to 100 nm, more preferably 60 to 80 nm). Conversely, in the case of the switching TFT 8201, from the viewpoint of reducing the off-state current, the thickness of the active layer (especially the channel formation region) may be reduced (preferably 20 to 50 nm, more preferably 25 to 40 nm). It is valid.
[0198]
Although the above has described the structure of the TFT provided in the pixel, a driving circuit is also formed at this time. FIG. 16 shows a CMOS circuit which is a basic unit for forming a driving circuit.
[0199]
In FIG. 16, a TFT having a structure that reduces hot carrier injection while reducing the operating speed as much as possible is used as the n-channel TFT 8204 of the CMOS circuit. Note that the driver circuit here refers to a source signal side driver circuit and a gate signal side driver circuit. Of course, other logic circuits (level shifter, A / D converter, signal dividing circuit, etc.) can be formed.
[0200]
An active layer of the n-channel TFT 8204 in the CMOS circuit includes a source region 835, a drain region 836, an LDD region 837, and a channel formation region 838. The LDD region 837 overlaps with the gate electrode 839 with the gate insulating film 818 interposed therebetween.
[0201]
The reason why the LDD region 837 is formed only on the drain region 836 side is to prevent the operation speed from being lowered. In addition, the n-channel TFT 8204 does not need to worry about the off-current value so much, and it is better to focus on the operation speed than that. Therefore, it is desirable that the LDD region 837 is completely overlapped with the gate electrode to reduce the resistance component as much as possible. That is, it is better to eliminate the so-called offset.
[0202]
Further, the p-channel TFT 8205 of the CMOS circuit is hardly concerned with deterioration due to hot carrier injection, so that it is not particularly necessary to provide an LDD region. Therefore, the active layer includes a source region 840, a drain region 841, and a channel formation region 842, on which a gate insulating film 818 and a gate electrode 843 are provided. Needless to say, it is possible to provide an LDD region as in the case of the n-channel TFT 8204 and take measures against hot carriers.
[0203]
861 to 865 are masks for forming channel formation regions 842, 838, 817a, 817b, and 829.
[0204]
Each of the n-channel TFT 8204 and the p-channel TFT 8205 has source signal lines 844 and 845 on the source region with a first interlayer insulating film 820 interposed therebetween. Further, the drain regions of the n-channel TFT 8204 and the p-channel TFT 8205 are electrically connected to each other by the drain wiring 846.
[0205]
Next, reference numeral 847 denotes a first passivation film, and the film thickness may be 10 nm to 1 μm (preferably 200 to 500 nm). As a material, an insulating film containing silicon (in particular, a silicon nitride oxide film or a silicon nitride film is preferable) can be used. The passivation film 847 has a role of protecting the formed TFT from alkali metal and moisture.
[0206]
Reference numeral 848 denotes a second interlayer insulating film having a function as a flattening film for flattening a step formed by the TFT. As the second interlayer insulating film 848, an organic resin film is preferable, and polyimide, polyamide, acrylic, BCB (benzocyclobutene), or the like is preferably used. These organic resin films have an advantage that they can easily form a good flat surface and have a low relative dielectric constant. Since the organic compound layer is very sensitive to unevenness, it is desirable that the step due to the TFT is almost absorbed by the second interlayer insulating film 848. Further, in order to reduce the parasitic capacitance formed between the gate signal line or data signal line and the cathode of the organic light emitting element, it is desirable to provide a thick material having a low relative dielectric constant. Therefore, the film thickness is preferably 0.5 to 5 μm (preferably 1.5 to 2.5 μm).
[0207]
Reference numeral 849 denotes a pixel electrode (anode of the organic light emitting device) made of a transparent conductive film, which is formed after opening a contact hole (opening) in the second interlayer insulating film 848 and the first passivation film 847. It is formed so as to be connected to the drain wiring 832 of the driving TFT 8202 in the portion.
[0208]
A third interlayer insulating film 850 made of a silicon oxide film, a silicon nitride oxide film, or an organic resin film is provided on the pixel electrode 849 to a thickness of 0.3 to 1 μm. The third interlayer insulating film 850 is etched so that an opening is formed on the pixel electrode 849 by etching, and the edge of the opening is tapered. The taper angle may be 10 to 60 ° (preferably 30 to 50 °).
[0209]
An organic compound layer 851 is provided on the third interlayer insulating film 850. The organic compound layer 851 is used in a single layer or a stacked structure, but the light emission efficiency is better when it is used in a stacked structure. In general, the hole injection layer / hole transport layer / light emitting layer / electron transport layer are formed on the pixel electrode in this order, but the hole transport layer / light emitting layer / electron transport layer, or hole injection layer / positive layer are formed. A structure such as a hole transport layer / a light emitting layer / an electron transport layer / an electron injection layer may be used. In the present invention, any known structure may be used, and the organic compound layer may be doped with a fluorescent dye or the like.
[0210]
The structure of FIG. 16 is an example in the case of using a method of forming three types of organic light emitting elements corresponding to RGB. Note that although only one pixel is shown in FIG. 16, pixels having the same structure are formed corresponding to the respective colors of red, green, and blue, whereby color display can be performed. The present invention can be implemented regardless of the light emission method.
[0211]
On the organic compound layer 851, a cathode 852 of an organic light emitting element is provided. As the cathode 852, a material containing magnesium (Mg) or calcium (Ca) having a low work function is used. Preferably, an electrode made of MgAg (a material in which Mg and Ag are mixed at a weight ratio of Mg: Ag = 10: 1) or AlMg (a material in which Mg and Al are mixed at a weight ratio of Mg: Ag = 5: 95) An electrode consisting of Other examples include MgAgAl electrodes.
[0212]
Note that an organic light-emitting element 8206 is formed by the pixel electrode (anode) 849, the organic compound layer 851, and the cathode 852.
[0213]
A stacked body including the organic compound layer 851 and the cathode 852 needs to be formed individually for each pixel. However, since the organic compound layer 851 is extremely vulnerable to moisture, a normal photolithography technique cannot be used. Accordingly, it is preferable to use a physical mask material such as a metal mask and selectively form the film by a vapor phase method such as a vacuum deposition method, a sputtering method, or a plasma CVD method.
[0214]
In addition, as a method for selectively forming the organic compound layer, an ink jet method, a screen printing method, a spin coating method, or the like can be used. It can be said that it is preferable.
[0215]
Reference numeral 853 denotes a protective electrode, which is an electrode for protecting the cathode 852 from external moisture and the like and simultaneously connecting the cathode 852 of each pixel. As the protective electrode 853, a low-resistance material containing aluminum (Al), copper (Cu), or silver (Ag) is preferably used. The protective electrode 853 can also be expected to have a heat dissipation effect that alleviates the heat generation of the organic compound layer.
[0216]
Reference numeral 854 denotes a second passivation film having a thickness of 10 nm to 1 μm (preferably 200 to 500 nm). The purpose of providing the second passivation film 854 is mainly to protect the organic compound layer 851 from moisture, but it is also effective to provide a heat dissipation effect. However, since the organic compound layer is vulnerable to heat as described above, it is desirable to form the film at as low a temperature as possible (preferably in a temperature range from room temperature to 120 ° C.). Therefore, it can be said that a plasma CVD method, a sputtering method, a vacuum deposition method, an ion plating method, or a solution coating method (spin coating method) is a preferable film forming method.
[0217]
Needless to say, all of the TFTs shown in FIG. 16 may have a polysilicon film used in the present invention as an active layer.
[0218]
In the light emitting device of this embodiment, when a pinhole is formed in the organic compound layer 860, a defective portion in which the pixel electrode 849 and the cathode 852 are in contact with each other through the pinhole is formed. According to the repair method of the present invention, the resistance can be increased by changing the defective portion to the modified portion 860. Therefore, it is possible to increase the luminance of portions other than the pinhole of the pixel and prevent the deterioration of the organic compound layer around the pinhole.
[0219]
The configuration of the present embodiment can be implemented by freely combining with the first, second, third, or eighth embodiment.
[0220]
Example 9
Since a light-emitting device using an organic light-emitting element is a self-luminous type, it has excellent visibility in a bright place and a wide viewing angle compared to a liquid crystal display device. Therefore, it can be used for display portions of various electronic devices.
[0221]
Electronic devices using light-emitting devices using the repair method of the present invention include video cameras, digital cameras, goggle type displays (head mounted displays), navigation systems, sound playback devices (car audio, audio components, etc.), notebook type personal computers. Computers, game machines, portable information terminals (mobile computers, mobile phones, portable game machines, electronic books, etc.), image playback devices equipped with recording media (specifically, playback of recording media such as digital video discs (DVDs)) And a device provided with a display device capable of displaying the image). In particular, a portable information terminal that often has an opportunity to see a screen from an oblique direction places importance on a wide viewing angle, and thus it is desirable to use a light emitting device having an organic light emitting element. Specific examples of these electronic devices are shown in FIGS.
[0222]
FIG. 11A illustrates a display device, which includes a housing 2001, a support base 2002, a display portion 2003, a speaker portion 2004, a video input terminal 2005, and the like. A light-emitting device manufactured using the repair method of the present invention can be used for the display portion 2003. Since a light-emitting device having an organic light-emitting element is a self-luminous type, a backlight is not necessary and a display portion thinner than a liquid crystal display device can be obtained. The display devices include all information display devices for personal computers, for receiving TV broadcasts, for displaying advertisements, and the like.
[0223]
FIG. 11B shows a digital still camera, which includes a main body 2101, a display portion 2102, an image receiving portion 2103, operation keys 2104, an external connection port 2105, a shutter 2106, and the like. The light-emitting device manufactured using the repair method of the present invention can be used for the display portion 2102.
[0224]
FIG. 11C illustrates a laptop personal computer, which includes a main body 2201, a housing 2202, a display portion 2203, a keyboard 2204, an external connection port 2205, a pointing mouse 2206, and the like. The light emitting device using the repair method of the present invention can be used for the display portion 2203.
[0225]
FIG. 11D illustrates a mobile computer, which includes a main body 2301, a display portion 2302, a switch 2304, operation keys 2305, an infrared port 2305, and the like. The light emitting device using the repair method of the present invention can be used for the display portion 2302.
[0226]
FIG. 11E illustrates a portable image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 2401, a housing 2402, a display portion A2403, a display portion B2404, and a recording medium (DVD or the like). A reading unit 2405, operation keys 2406, a speaker unit 2407, and the like are included. Although the display portion A 2403 mainly displays image information and the display portion B 2404 mainly displays character information, a light-emitting device using the repair method of the present invention can be used for these display portions A, B 2403 and 2404. Note that home video game machines and the like are included in the image reproducing device provided with the recording medium.
[0227]
FIG. 11F illustrates a goggle type display (head mounted display), which includes a main body 2501, a display portion 2502, and an arm portion 2503. The light emitting device using the repair method of the present invention can be used for the display portion 2502.
[0228]
FIG. 11G illustrates a video camera, which includes a main body 2601, a display portion 2602, a housing 2603, an external connection port 2604, a remote control receiving portion 2605, an image receiving portion 2606, a battery 2607, an audio input portion 2608, operation keys 2609, and the like. . The light emitting device using the repair method of the present invention can be used for the display portion 2602.
[0229]
Here, FIG. 11H shows a mobile phone, which includes a main body 2701, a housing 2702, a display portion 2703, an audio input portion 2704, an audio output portion 2705, operation keys 2706, an external connection port 2707, an antenna 2708, and the like. The light emitting device using the repair method of the present invention can be used for the display portion 2703. Note that the display portion 2703 can reduce power consumption of the mobile phone by displaying white characters on a black background.
[0230]
If the emission brightness of the organic compound material is increased in the future, the light including the output image information can be enlarged and projected by a lens or the like and used for a front type or rear type projector.
[0231]
In addition, the electronic devices often display information distributed through electronic communication lines such as the Internet and CATV (cable television), and in particular, opportunities to display moving image information are increasing. Since the response speed of the organic compound material is very high, the light-emitting device is preferable for displaying moving images.
[0232]
Further, since the light emitting part consumes power in the light emitting device, it is desirable to display information so that the light emitting part is minimized. Therefore, when a light emitting device is used for a display unit mainly including character information, such as a portable information terminal, particularly a mobile phone or a sound reproduction device, it is driven so that character information is formed by the light emitting part with the non-light emitting part as the background. It is desirable to do.
[0233]
As described above, the applicable range of the light-emitting device using the repair method of the present invention is so wide that the light-emitting device can be used for electronic devices in various fields. In addition, any configuration shown in the first to seventh embodiments may be used for the electronic apparatus of the present embodiment.
[0234]
(Example 10)
In this embodiment, a case where the repair method of the present invention is applied to a passive (simple matrix) light emitting device will be described.
[0235]
FIG. 20A illustrates a structure of a passive light-emitting device. Reference numeral 905 denotes a pixel portion, which has a plurality of pixels 906. Each pixel has one of a plurality of data lines 903 and one of a plurality of scanning lines 904. An organic compound layer is formed between the data line 903 and the scanning line 904, and the data line 903 and the scanning line 904 serve as electrodes to form an organic light emitting element 907.
[0236]
A signal input to the data line 903 is controlled by the data line driver circuit 901, and a signal input to the scan line 904 is controlled by the scan line driver circuit 902.
[0237]
FIG. 20B shows the voltage levels of signals input to the scanning line 904 and the data line 903 when the repair method of the present invention is used. By making the voltage of each scanning line 904 constant and changing the voltage of the data line every fixed period, a current of a predetermined reverse bias is supplied to the organic light emitting element 907 every fixed period.
[0238]
The defect repair of the organic light emitting element 907 may be performed simultaneously for all the pixels 906 included in the pixel portion 905, or may be performed for each line or for each pixel.
[0239]
By using the method of the present invention, a pinhole is formed due to the influence of dust or the like during the formation of the organic compound layer, and even if two layers formed with the organic compound layer sandwiched therebetween are short-circuited, they are short-circuited. The resistance of the defective portion can be increased, and the current that actually flows through the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting device. Therefore, the repairing method of the present invention can increase the light emission luminance when the same voltage is applied even if a defect exists.
[0240]
In addition, since a current always flows in the defect portion, the deterioration of the organic compound layer existing around the defect portion is easily promoted. However, the modified layer has a resistance R _SC Therefore, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer.
[0241]
This embodiment can be implemented by freely combining with Embodiments 4, 5, and 9.
[0242]
【The invention's effect】
According to the present invention, a pinhole is formed due to the influence of dust or the like during the formation of an organic compound layer, and even if two layers formed with the organic compound layer in between are short-circuited, the short-circuited defect The resistance of the portion can be increased, and the current that actually flows through the organic compound layer can be increased when a forward bias voltage is applied to the organic light emitting device. Therefore, the repairing method of the present invention can increase the light emission luminance when the same voltage is applied even if a defect exists.
[0243]
In addition, since a current always flows in the defect portion, the deterioration of the organic compound layer existing around the defect portion is easily promoted. However, the modified layer has a resistance R _SC Therefore, it is difficult for current to flow, and it is possible to prevent the deterioration of the organic compound layer existing around the modified layer.
[0244]
Furthermore, by preventing Na and Li from being contained as much as possible in the cathode of the organic light emitting element, it is possible to prevent contamination of devices such as the organic light emitting element and TFT when a reverse bias is applied to the organic light emitting element.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating a current flow in an organic light emitting device when a reverse bias voltage is applied to the organic light emitting device.
FIG. 2 is a diagram schematically showing a change in voltage-current characteristics of an organic light emitting device during a repair process and a current flow in the organic light emitting device when a forward bias voltage is applied to the repaired organic light emitting device. .
3 is a circuit diagram of a pixel according to Embodiment 1. FIG.
FIG. 4 is a circuit diagram of a pixel unit according to the first exemplary embodiment and a diagram illustrating an operation of the pixel unit during repair.
5 is a circuit diagram of a pixel according to Embodiment 2. FIG.
FIG. 6 is a circuit diagram of a pixel portion according to the second embodiment and a diagram illustrating an operation of the pixel portion during repair.
7 is a circuit diagram of a pixel portion according to a third embodiment and a diagram illustrating an operation of the pixel portion during repair. FIG.
8 is a circuit diagram of a pixel according to Embodiment 3. FIG.
FIG. 9 is a diagram showing a configuration of an organic light-emitting device of Example 4.
10 is a diagram showing a configuration of an organic light-emitting device of Example 4. FIG.
11 shows an electronic apparatus having a light emitting device using the repair method of the present invention in Example 10. FIG.
FIG. 12 is a cross-sectional view of an organic light emitting device having a defective portion, and a diagram schematically showing a current flow when a forward bias current is passed through the organic light emitting device.
FIG. 13 is a graph showing voltage-current characteristics of an organic light-emitting element.
14 is a cross-sectional view of a light-emitting device of Example 5. FIG.
15 is a cross-sectional view of a light-emitting device of Example 6. FIG.
16 is a cross-sectional view of a light-emitting device of Example 7. FIG.
FIG. 17 is a diagram showing a MOS structure using AlMg as an electrode and capacitance-voltage characteristics.
FIG. 18 is a diagram showing a MOS structure using MgAg as an electrode and capacitance-voltage characteristics.
FIG. 19 is a diagram showing a MOS structure using AlLi as an electrode and capacitance-voltage characteristics.
FIG. 20 is a diagram in the case where the repair method of the present invention is used for a passive light-emitting device.

Claims (11)

A light emitting element having a pixel electrode , a counter electrode , the pixel electrode and an organic compound layer sandwiched between the counter electrode , a switching thin film transistor, and a driving thin film transistor electrically connected to the switching thin film transistor; A reverse bias applying thin film transistor electrically connected to the driving thin film transistor; and a power supply line electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor;
The pixel electrode is a repair method of an active matrix light emitting device in which the pixel electrode is electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor ,
The cathode which is either the pixel electrode or the counter electrode is an MgAg alloy having a Li or Na content of 1 × 10 ¹⁸ atoms / cm ³ or less ,
When repairing by applying a reverse bias voltage between the pixel electrode and the counter electrode ,
Turning off the switching thin film transistor;
Turning off the driving thin film transistor;
Turn on the reverse bias applying thin film transistor,
Make the voltage of the power supply line constant,
A method of repairing an active matrix light-emitting device, wherein the voltage of the counter electrode is changed . A light emitting element having a pixel electrode , a counter electrode , the pixel electrode and an organic compound layer sandwiched between the counter electrode , a switching thin film transistor, and a driving thin film transistor electrically connected to the switching thin film transistor; A reverse bias applying thin film transistor electrically connected to the driving thin film transistor; and a power supply line electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor;
The pixel electrode is a repair method of an active matrix light emitting device in which the pixel electrode is electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor ,
The cathode which is either the pixel electrode or the counter electrode is an MgAg alloy having a Li or Na content of 1 × 10 ¹⁸ atoms / cm ³ or less ,
When repairing by applying a reverse bias voltage between the pixel electrode and the counter electrode ,
Turning off the switching thin film transistor;
Turning off the driving thin film transistor;
Turn on the reverse bias applying thin film transistor,
Make the voltage of the power supply line constant,
Changing the voltage of the counter electrode;
An active matrix type light emission characterized in that a current is passed through a portion where the pixel electrode and the counter electrode are electrically short-circuited to generate heat, and the heat-generated portion is increased in resistance or insulation. How to repair the device. A light emitting element having a pixel electrode , a counter electrode , the pixel electrode and an organic compound layer sandwiched between the counter electrode , a switching thin film transistor, and a driving thin film transistor electrically connected to the switching thin film transistor; A reverse bias applying thin film transistor electrically connected to the driving thin film transistor; and a power supply line electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor;
The pixel electrode is a repair method of an active matrix light emitting device in which the pixel electrode is electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor ,
The cathode which is either the pixel electrode or the counter electrode is an MgAg alloy having a Li or Na content of 1 × 10 ¹⁸ atoms / cm ³ or less ,
When repairing by applying a reverse bias voltage between the pixel electrode and the counter electrode ,
Turning off the switching thin film transistor;
Turning off the driving thin film transistor;
Turn on the reverse bias applying thin film transistor,
Make the voltage of the power supply line constant,
Changing the voltage of the counter electrode;
An active matrix light-emitting device, wherein at least one of the pixel electrode or the counter electrode is inserted into the organic compound layer, and a current is passed through a portion where the pixel electrode and the counter electrode are electrically short-circuited. Repair method. In claim 3,
A method of repairing an active matrix light-emitting device, wherein the current is supplied to a portion where the pixel electrode and the counter electrode are in electrical contact to generate heat, and the generated portion is increased in resistance or insulation. In any one of Claims 1 thru | or 4,
The method for repairing an active matrix light-emitting device, wherein the cathode has a Mg content of 1 × 10 ²⁰ atoms / cm ³ or more. In any one of Claims 1 thru | or 5,
Either the source or drain of the switching thin film transistor and the gate electrode of the driving thin film transistor are electrically connected,
Either the source or drain of the driving thin film transistor and the power supply line are electrically connected,
The other one of the source and drain of the driving thin film transistor and the pixel electrode are electrically connected,
Either the source or drain of the thin film transistor for reverse bias application and the power supply line are electrically connected,
The pixel electrode is electrically connected to either the source or drain of the thin film transistor for reverse bias application,
A method of repairing an active matrix light emitting device, wherein a gate electrode of the reverse bias applying thin film transistor and the power supply line are electrically connected. In any one of Claims 1 thru | or 6,
A method for repairing an active matrix light-emitting device, wherein the reverse bias voltage is applied a plurality of times at regular intervals. In any one of Claims 1 thru | or 6,
Active matrix light-emitting device comprising the possible gradually to increase the reverse bias voltage to fall within ± 15% of the organic compound layer to the voltage starts to flow avalanche E current when a voltage of the reverse bias Repair method. A light emitting element having a pixel electrode , a counter electrode , the pixel electrode and an organic compound layer sandwiched between the counter electrode , a switching thin film transistor, and a driving thin film transistor electrically connected to the switching thin film transistor; A reverse bias applying thin film transistor electrically connected to the driving thin film transistor; and a power supply line electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor;
The pixel electrode is a manufacturing method of an active matrix light emitting device in which the driving thin film transistor and the reverse bias applying thin film transistor are electrically connected ,
Li or Na content is 1 × 10 ¹⁸ atoms / cm ³ or less, and after forming a cathode which is either the pixel electrode or the counter electrode made of an MgAg alloy , the pixel electrode and the counter electrode are formed. When applying a reverse bias voltage between the electrodes ,
Turning off the switching thin film transistor;
Turning off the driving thin film transistor;
Turn on the reverse bias applying thin film transistor,
Make the voltage of the power supply line constant,
A method for manufacturing an active matrix light-emitting device, wherein the voltage of the counter electrode is changed . A light emitting element having a pixel electrode , a counter electrode , the pixel electrode and an organic compound layer sandwiched between the counter electrode , a switching thin film transistor, and a driving thin film transistor electrically connected to the switching thin film transistor; A reverse bias applying thin film transistor electrically connected to the driving thin film transistor; and a power supply line electrically connected to the driving thin film transistor and the reverse bias applying thin film transistor;
The pixel electrode is a manufacturing method of an active matrix light emitting device in which the driving thin film transistor and the reverse bias applying thin film transistor are electrically connected ,
Li or Na content is 1 × 10 ¹⁸ atoms / cm ³ or less, and after forming a cathode which is either the pixel electrode or the counter electrode made of an MgAg alloy , the pixel electrode and the counter electrode are formed. When applying a reverse bias voltage between the electrodes ,
Turning off the switching thin film transistor;
Turning off the driving thin film transistor;
Turn on the reverse bias applying thin film transistor,
Make the voltage of the power supply line constant,
Changing the voltage of the counter electrode;
An active matrix light emitting device characterized in that a current is passed through a portion where the pixel electrode and the counter electrode are electrically short-circuited, the short-circuited portion is heated, and the heated portion is increased in resistance or insulation. Device fabrication method. In claim 9 or claim 10,
Either the source or drain of the switching thin film transistor and the gate electrode of the driving thin film transistor are electrically connected,
Either the source or drain of the driving thin film transistor and the power supply line are electrically connected,
The other one of the source and drain of the driving thin film transistor and the pixel electrode are electrically connected,
Either the source or drain of the thin film transistor for reverse bias application and the power supply line are electrically connected,
The pixel electrode is electrically connected to either the source or drain of the thin film transistor for reverse bias application,
A method for manufacturing an active matrix light-emitting device, wherein a gate electrode of the reverse bias applying thin film transistor and the power supply line are electrically connected.

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