JP4637391B2 - Method for manufacturing light emitting device - Google Patents

Description

【０１８９】
(M.A.Baldo, D.F.O'Brien, Y.You, A.Shoustikov, S.Sibley, M.E.Thompson, S.R.Forrest, Nature 395 (1998) p.151.)
上記論文に報告されたＥＬ材料（Ｐｔ錯体）の分子式を以下に示す。
【０１９０】
【化２】

【０１９１】
(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.)
上記論文に報告されたＥＬ材料（Ｉｒ錯体）の分子式を以下に示す。
【０１９２】
【化３】

【０１９３】
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。なお、本実施例の構成は、実施例１〜実施例９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。
【０１９４】
〔実施例１２〕
本発明を実施して形成された発光装置は、自発光型であるため液晶表示装置に比べて明るい場所での視認性に優れ、しかも視野角が広い。従って、様々な電気器具の表示部として用いることができる。その際、本発明の発光装置はパッシブ型の発光装置でありながらも配線抵抗を減らすことで大画面化を可能としているため、用途も幅広いものとすることができる。
【０１９５】
本発明の電気器具としては、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）、カーナビゲーションシステム、カーオーディオ、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）、記録媒体を備えた画像再生装置（具体的にはコンパクトディスク（ＣＤ）、レーザーディスク（ＬＤ）又はデジタルバーサタイルディスク（ＤＶＤ）等の記録媒体を再生し、その画像を表示しうるディスプレイを備えた装置）などが挙げられる。それら電気器具の具体例を図２０、図２１に示す。
【０１９６】
図２０（Ａ）はＥＬディスプレイであり、筐体２００１、支持台２００２、表示部２００３を含む。本発明の発光装置は表示部２００３に用いることができる。ＥＬディスプレイは自発光型であるためバックライトが必要なく、液晶ディスプレイよりも薄い表示部とすることができる。なお、表示部２００３に用いる発光装置にスティックドライバを設ける場合は、数十個に分割して設けることが好ましい。
【０１９７】
図２０（Ｂ）はビデオカメラであり、本体２１０１、表示部２１０２、音声入力部２１０３、操作スイッチ２１０４、バッテリー２１０５、受像部２１０６を含む。本発明の発光装置は表示部２１０２に用いることができる。なお、表示部２１０２に用いる発光装置にスティックドライバを設ける場合は、数個に分割して設けることが好ましい。
【０１９８】
図２０（Ｃ）はデジタルカメラであり、本体２２０１、表示部２２０２、接眼部部２２０３、操作スイッチ２２０４を含む。本発明の発光装置は表示部２２０２に用いることができる。なお、表示部２２０２に用いる発光装置にスティックドライバを設ける場合は、数個に分割して設けることが好ましい。
【０１９９】
図２０（Ｄ）は記録媒体を備えた画像再生装置（具体的にはＤＶＤ再生装置）であり、本体２３０１、記録媒体（ＣＤ、ＬＤまたはＤＶＤ等）２３０２、操作スイッチ２３０３、表示部（ａ）２３０４、表示部（ｂ）２３０５を含む。表示部（ａ）は主として画像情報を表示し、表示部（ｂ）は主として文字情報を表示するが、本発明の発光装置はこれら表示部（ａ）、（ｂ）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、ＣＤ再生装置、ゲーム機器なども含まれうる。なお、表示部（ａ）２３０４、表示部（ｂ）２３０５に用いる発光装置にスティックドライバを設ける場合は、数十個に分割して設けることが好ましい。
【０２００】
図２０（Ｅ）は携帯型（モバイル）コンピュータであり、本体２４０１、表示部２４０２、受像部２４０３、操作スイッチ２４０４、メモリスロット２４０５を含む。本発明の電気光学装置は表示部２４０２に用いることができる。この携帯型コンピュータはフラッシュメモリや不揮発性メモリを集積化した記録媒体に情報を記録したり、それを再生したりすることができる。なお、表示部２４０２に用いる発光装置にスティックドライバを設ける場合は、数個に分割して設けることが好ましい。
【０２０１】
図２０（Ｆ）はパーソナルコンピュータであり、本体２５０１、筐体２５０２、表示部２５０３、キーボード２５０４を含む。本発明の発光装置は表示部２５０３に用いることができる。なお、表示部２５０３に用いる発光装置にスティックドライバを設ける場合は、数十個に分割して設けることが好ましい。
【０２０２】
なお、将来的にＥＬ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。
【０２０３】
また、上記電子装置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。ＥＬ材料の応答速度は非常に高いため、そのような動画表示を行うに適している。
【０２０４】
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、特に携帯電話やカーオーディオ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。
【０２０５】
ここで図２１（Ａ）は携帯電話であり、本体２６０１、音声出力部２６０２、音声入力部２６０３、表示部２６０４、操作スイッチ２６０５、アンテナ２６０６を含む。本発明の発光装置は表示部２６０４に用いることができる。なお、表示部２６０４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。
【０２０６】
また、図２１（Ｂ）はカーオーディオであり、本体２７０１、表示部２７０２、操作スイッチ２７０３、２７０４を含む。本発明の発光装置は表示部２７０２に用いることができる。また、本実施例では車載用カーオーディオを示すが、据え置き型のカーオーディオに用いても良い。なお、表示部２７０４は黒色の背景に白色の文字を表示することで消費電力を抑えられる。なお、表示部２７０４に用いる発光装置にスティックドライバを設ける場合は、数個に分割して設けることが好ましい。
【０２０７】
以上の様に、本発明の適用範囲は極めて広く、あらゆる分野の電気器具に用いることが可能である。また、本実施例の電気器具は実施例１〜１０の構成を自由に組み合わせた発光装置を用いることで得ることができる。
【０２０８】
【発明の効果】
本発明を実施することでＥＬ材料を成膜するにあたって成膜位置を精密に制御することが可能となる。そのため高精細な画素部を有する発光装置を作製することができる。また、必要な部分に優先的にＥＬ材料を成膜することができるため、ＥＬ材料の利用効率が高まり、製造コストを低減することができる。さらに、本発明の発光装置を表示部として用いることで高精細な表示部を有した電気器具を得ることができる。
【図面の簡単な説明】
【図１】 発光装置の上面構造および断面構造を示す図。
【図２】 ＥＬ材料の成膜工程を説明するための図。
【図３】 蒸着法によるＥＬ材料の成膜工程を説明するための図。
【図４】 インクジェット法によるＥＬ材料の成膜工程を説明するための図。
【図５】 イオンプレーティング法によるＥＬ材料の成膜工程を説明するための図。
【図６】 発光装置の画素部の断面構造を示す図。
【図７】 発光装置の画素部の上面構造および回路構成を示す図。
【図８】 発光装置の作製方法を示す図。
【図９】 発光装置の作製方法を示す図。
【図１０】 発光装置の作製方法を示す図。
【図１１】 スイッチング用ＴＦＴの構造を示す図。
【図１２】 電流制御用ＴＦＴの構造を示す図。
【図１３】 発光装置の外観を示す図。
【図１４】 発光装置の回路構成を示す図。
【図１５】 発光装置の上面構造および断面構造を示す図。
【図１６】 多面取りプロセスを説明するための図。
【図１７】 多面取りプロセスを説明するための図。
【図１８】 ＥＬ材料の成膜工程を説明するための図。
【図１９】 ＥＬ材料の成膜工程を説明するための図。
【図２０】 電気器具の一例を示す図。
【図２１】 電気器具の一例を示す図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device (hereinafter referred to as a light-emitting device) having an element (hereinafter referred to as a light-emitting device) in which a light-emitting material is sandwiched between electrodes and a manufacturing method thereof. In particular, the present invention relates to a light emitting device (hereinafter referred to as EL light emitting device) using a light emitting element (hereinafter referred to as EL element) using a light emitting material (hereinafter referred to as EL material) from which EL (Electro Luminescence) can be obtained as a light emitting material. An organic EL display and an organic light emitting diode (OLED) are included in the light emitting device of the present invention.
[0002]
The EL material that can be used in the present invention includes all luminescent materials that emit light (phosphorescence and / or fluorescence) through singlet excitation, triplet excitation, or both excitation.
[0003]
[Prior art]
An EL light emitting device has a structure having an EL element having a structure in which an EL material is sandwiched between an anode and a cathode. By applying a voltage between the anode and the cathode and passing a current through the EL material, carriers are recombined to emit light. That is, since the EL light emitting device has a light emitting capability, the backlight used for the liquid crystal display device is unnecessary. Furthermore, it has the advantages of a wide viewing angle and light weight.
[0004]
At this time, in order to form an EL layer by forming an EL material, various film forming methods are employed. In particular, a vapor deposition method is used for forming a low molecular weight organic EL material, and a spin coating method or an ink jet method is used for forming a high molecular weight organic EL material.
[0005]
Each film formation method has advantages and disadvantages, but the vapor deposition method has a problem that the utilization efficiency of the EL material is poor. In the case of the vapor deposition method, the EL material evaporated by resistance heating or electron beam heating is scattered to form a film. In addition to the film formed on the film forming surface, the film is formed on the vapor deposition mask (shadow mask) and the inner wall of the vapor deposition chamber. The loss of being done was great. Since the unit price of EL material is high at present, such a problem results in an increase in manufacturing cost.
[0006]
In addition, in the case of the ink jet method, it is difficult to control the trajectory of the droplet containing the EL material discharged from the nozzle tip, and it is difficult to accurately control the landing point (portion where the EL layer is formed) of the droplet. If this landing point is deviated, there may be a problem that a droplet is mixed into the adjacent pixel. This problem becomes a particularly significant problem in manufacturing a light-emitting device having a high-definition pixel portion.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a technique for precisely controlling the deposition position when depositing an EL material. Another object is to obtain a light-emitting device having a high-definition pixel portion. It is another object of the present invention to provide an electric appliance with high display quality using the light emitting device as a display portion.
[0008]
[Means for Solving the Problems]
In the present invention, a metal film is used as part of a bank for dividing pixels, and an electric field is formed by applying a voltage (negatively or positively) to the metal film, and the trajectory of the EL material is controlled by the electric field. It is characterized by that. Therefore, in this specification, “applying an electric field” is synonymous with “controlling the direction of charged particles”.
[0009]
Note that in this specification, a “bank” refers to a stacked body of an insulating film and a conductive film provided so as to surround a pixel electrode, and plays a role of partitioning individual pixels. Further, in the present specification, for the sake of clarity, the present invention is divided into parts and distinguished by the names “support bank” and “control bank”.
[0010]
With the above-described configuration, the deposition position of the EL material is precisely controlled in the deposition method in which the EL material flies and adheres from above or below the coating formation surface, such as an evaporation method, an ion plating method, or an inkjet method. Thus, a light-emitting device having a high-definition pixel portion can be obtained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The structure of the light-emitting device of the present invention will be described with reference to FIGS. 1A is a top view of the pixel portion, and FIG. 1B is a cross-sectional view taken along line AA ′ in FIG. 1A. Note that the light-emitting device shown here is in a state before the light-emitting element is sealed.
[0012]
In the light-emitting device of the present invention, a TFT 102 is first provided over an insulator 101. The insulator 101 may be a glass substrate, a plastic substrate (including a plastic film), a metal substrate or a ceramic substrate provided with an insulating film, or a quartz substrate may be used as it is.
[0013]
The TFT (thin film transistor) 102 may be an n-channel TFT or a p-channel TFT having a known structure, and even a top gate structure (typically a planar TFT) has a bottom gate structure (typically an inverted staggered TFT). Type TFT). The arrangement of TFTs is not limited, but typically, a pixel structure described in Japanese Patent Application Laid-Open No. 5-107561 by the present applicant may be adopted.
[0014]
The TFT 102 is covered with an interlayer insulating film 103, and the pixel electrode 104 is electrically connected with the interlayer insulating film 103 interposed therebetween. As the interlayer insulating film 103, an insulating film containing silicon, typically a silicon oxide film, a silicon nitride film, a silicon nitride oxide film, or a silicon carbide film can be used. Further, a resin film can be used, or a resin film and an insulating film containing silicon can be combined.
[0015]
Here, a conductive film having a high work function is used as the pixel electrode 104, and an oxide conductive film that is transparent to visible light is typically used. As the oxide conductive film, a conductive film made of indium oxide, tin oxide, zinc oxide, or a compound thereof can be used. Further, gallium may be added to these oxide conductive films.
[0016]
A bank 105 is provided so as to surround the pixel electrode 104. The bank 105 includes a support bank 105a made of an insulating film and a control bank 105b made of a metal film provided thereon. At this time, the line width of the control bank 105b is narrower than the line width of the support bank 105a. Furthermore, the support bank 105a and the control bank 105b are preferably tapered. In the present invention, the flight path of the EL material can be controlled by applying a voltage having a polarity different from that of the pixel electrode to the control bank 105b to be negatively or positively charged and applying an electric field to the EL material.
[0017]
Further, an EL layer 106 is provided in the pixel surrounded by the bank 105, and a cathode 107 is provided so as to cover the bank 105 and the EL layer 106.
[0018]
Note that in this specification, an EL layer refers to an insulating layer provided between an anode and a cathode in an EL element, and is a layer formed by combining various organic films or inorganic films. Typically, the EL layer includes at least a light emitting layer, and the light emitting layer is used in combination with a charge injection layer or a charge transport layer. As the EL layer 106, an organic EL material, an inorganic EL material, or an EL material that is a combination thereof is used. Moreover, when using an organic EL material, a low molecular material or a high molecular material may be used, and any known material may be used.
[0019]
For the cathode 107, a conductive film having a low work function is used, and a conductive film containing an element belonging to Group 1 or Group 2 of the periodic table is typically used. Typically, an alloy film containing magnesium, lithium, cesium, beryllium, potassium, or calcium is used. A bismuth film can also be used.
[0020]
The pixel electrode (anode) 104, the EL layer 106, and the cathode 107 form the EL element 100. Actually, the EL element 100 is protected from the outside air by providing a resin film as a sealing material on the EL element 100 or creating a sealed space on the EL element 100. This is because the EL layer 106 and the cathode 107 are deteriorated by oxidation, so that oxygen and water are avoided as much as possible.
[0021]
When the light emitting device of the present invention including the above structure uses a method of forming a film by adhering an EL material from above or below, such as an evaporation method, an ion plating method, or an ink jet method. In this case, an electric field is applied to the EL material by using a metal film that is a part of the bank, and the deposition position is controlled by the electric field.
[0022]
By implementing the present invention, an EL material can be formed while performing precise position control, and a light-emitting device having a high-definition pixel portion can be realized.
[0023]
【Example】
[Example 1]
A process for forming an EL layer in manufacturing the light-emitting device having the structure shown in FIG. 1 will be described with reference to FIGS. A part of the description will be given with reference to the reference numerals in FIG.
[0024]
In FIG. 2A, a TFT 102 is formed over an insulator 101, and a pixel electrode (here functioning as an anode) 104 is formed over an interlayer insulating film 103 formed so as to cover the TFT 102. . Further, a bank 105 including a support bank 105 a and a control bank 105 b is formed so as to surround the pixel electrode 104.
[0025]
In this state, the pixel electrode 104 is first positively charged. In this case, a positive voltage may be applied to the pixel electrode 104, or charging may be performed by taking a positively charged ion shower. When applying a positive voltage, the TFT 102 may be operated and applied. The control bank 105b is negatively charged. This is possible by applying a negative voltage to the control bank 105b. The practitioner may determine the magnitude of the negative voltage as appropriate.
[0026]
In this state, an EL material 201 (hereinafter referred to as an EL material including a solution containing the EL material) 201 is stacked by an evaporation method, an ion plating method, or an inkjet method. At this time, the present invention is characterized in that the EL material 201 is charged to the same polarity as that of the control bank 105b. That is, in this embodiment, since the control bank 105b is negatively charged, the EL material 201 is also negatively charged. As a result, the EL material 201 repels the electric field formed around the control bank 105b and draws a trajectory that avoids the control bank 105b.
[0027]
Further, in this embodiment, since the pixel electrode 104 is positively charged, the pixel material 104 works in a direction to attract the negatively charged EL material 201.
[0028]
As described above, the EL material 201 is stacked on the pixel electrode 104 while avoiding the control bank 105b. Thus, the EL layer 202 is formed in the pixel portion. That is, without providing a shadow mask or the like, it is possible to concentrate the EL material on the pixel and to greatly improve the use efficiency of the EL material.
[0029]
Further, the present invention can be implemented without any problem even in a very fine pixel portion having a pixel pitch of several tens of μm. The method of stacking EL materials using a shadow mask has a problem with the alignment accuracy of the shadow mask, and is not suitable for forming a high-definition pixel portion. In such a case, it can be said that implementing the present invention is very effective.
[0030]
[Example 2]
In this embodiment, FIG. 3 shows a case where the present invention is carried out when an EL material is formed by vapor deposition.
[0031]
In FIG. 3, reference numeral 301 denotes an evaporation chamber, and a partition wall 302 of the evaporation chamber is connected to a negative power source 303 to which a negative voltage is applied. A vapor deposition boat 304 is installed inside the vapor deposition chamber 301, and a solid EL material 305 is provided therein. The vapor deposition boat 304 is heated using power supplies 307 a and 307 b connected to the support base 306. That is, in this embodiment, a vapor deposition source by resistance heating is used.
[0032]
In addition, an EL material that has become a gas that has come out of the hole (hereinafter referred to as a gas EL material) immediately outside a hole provided in the vapor deposition boat 304 (a hole for the EL material that has become a gas to go out of the vapor deposition boat). A ring-shaped electrode 320 is provided so as to surround the electrode. The ring-shaped electrode 320 is connected to a negative power source 308 and forms an electric field inside the ring-shaped electrode 320 to negatively charge the gas EL material. That is, the gas EL material that has jumped out of the vapor deposition boat 304 is charged by passing an electric field during the scattering. At this time, since the partition wall 302 in the vapor deposition chamber is negatively charged, EL material adhering to the partition wall 302 can be minimized.
[0033]
The scattered gas EL material 309 is stacked on the pixel electrode 311 so as to avoid the electric field formed by the control bank 310. A negative power source 312 is connected to the control bank 310, thereby forming an electric field. Although not shown, all control banks are electrically connected so as to have the same potential.
[0034]
At this time, a positive power source 314 is connected to the source wiring of the TFT 313 to which the pixel electrode 311 is connected, so that a positive voltage can be applied to the pixel electrode 311. Further, the substrate 315 having the TFT 313 is held by the susceptor 316. The susceptor 316 may be negatively charged during film formation.
[0035]
The pixel electrode 311 is positively charged by being applied with a positive voltage by operating the electrically connected TFT 313. That is, this embodiment is also characterized in that the EL material is stacked while the TFT 313 is operated. Of course, the TFT 313 is not necessarily operated.
[0036]
With the above-described configuration, it is possible to increase the utilization efficiency of the vaporized EL material 309 and form a desired EL layer with a minimum amount. Therefore, the consumption of the EL material is greatly reduced, so that the manufacturing cost can be reduced.
[0037]
In addition, although resistance heating was taken as an example as an evaporation source, electron beam (EB) heating may be used.
[0038]
In this embodiment, the gas EL material is negatively charged. However, the gas EL material can be positively charged. In that case, the partition 302, the evaporation boat 304, and the control bank 310 may be positively charged, and the pixel electrode 311 may be negatively charged.
[0039]
Example 3
In this embodiment, FIG. 4 shows a case where the present invention is carried out when an EL material is applied by an ink jet method. 4A and 4B are performed in an inert atmosphere (in nitrogen gas or rare gas).
[0040]
In FIG. 4A, 401 is a glass substrate, 402 is a TFT, 403 is a pixel electrode functioning as an anode, and a positive power supply 404 is connected to the source wiring of the TFT 402. In this embodiment, a negative power source 406 is connected to the control bank 405. In this case, although not shown, all the control banks are electrically connected so as to have the same potential.
[0041]
Above the substrate 401, heads 407 to 409 of a thin film forming apparatus for laminating EL materials by an ink jet method are arranged. The head 407 includes a solution 410 containing an EL material for red light emission, the head 408 includes a solution 411 containing an EL material for green light emission, and the head 409 emits a blue light emission. A solution 412 containing EL material for is provided. Solutions containing these EL materials are discharged using a piezo element. Of course, a bubble jet method may be used.
[0042]
In this embodiment, negative power sources 413 to 415 are connected to the heads 407 to 409, respectively, and the EL materials 410 to 412 are negatively charged. The solution containing the EL material discharged in this state falls along a trajectory indicated by a dotted line, and is applied onto the pixel electrode 403 exposed between the banks. That is, the solutions 410 to 412 containing the EL material that is negatively charged are applied to the pixels while avoiding the control bank 405 that is also negatively charged.
[0043]
Thus, an EL layer 416 corresponding to red light emission, an EL layer 417 corresponding to green light emission, and an EL layer 418 corresponding to blue light emission are formed in the pixel. Note that although only three pixels are illustrated here, it may be formed one pixel at a time or may be formed simultaneously on a plurality of three or more pixels.
[0044]
FIG. 4B shows an example in which an electrode for charging a solution containing an EL material is provided in the vicinity of the discharge ports of the heads 407 to 409. In this embodiment, an extraction electrode 421, an acceleration electrode 422, and a control electrode 423 are provided. Further, a power source 424 is connected to each.
[0045]
The extraction electrode 421 is an electrode that forms an electric field for extracting a solution containing an EL material from the heads 407 to 409. The acceleration electrode 422 is an electrode for forming an electric field for accelerating the extracted EL material, and the control electrode 423 is an electrode for forming an electric field for finally controlling the position where the EL material falls. Of course, it is not always necessary to use these three, and it is not necessary to limit to this combination.
[0046]
In the case of the structure shown in FIG. 4B, the solution containing the EL material is negatively charged using any of these three electrodes. Therefore, it is not necessary to provide a power source for the heads 407 to 409, and the solution itself containing the discharged EL material can be directly charged. Also in this case, as in the case of FIG. 4A, the solution containing the EL material falls along the trajectory indicated by the dotted line, and is applied onto the pixel electrode 403 exposed between the banks. That is, the negatively charged EL materials 409 to 411 are applied to the pixels while avoiding the negatively charged control bank 404.
[0047]
With the above configuration, the possibility that the trajectory is shifted when applying the EL material by the ink jet method is greatly reduced, and the yield can be improved. Therefore, the manufacturing cost can be reduced.
[0048]
Note that although an example in which a solution containing an EL material is negatively charged is shown in this embodiment, it can also be positively charged. In that case, the control bank 405 and the solutions 410 to 412 containing the EL material may be positively charged, and the pixel electrode 403 may be negatively charged.
[0049]
Example 4
In this embodiment, FIG. 5 shows a case where the present invention is carried out when an EL layer is formed by an ion plating method.
[0050]
In FIG. 5, reference numeral 501 denotes a vapor deposition chamber, and a partition wall 502 of the vapor deposition chamber is connected to a positive power source 503 to which a positive voltage is applied. Further, a vapor deposition boat 504 is installed inside the vapor deposition chamber 501, and a solid EL material 505 is provided therein. The vapor deposition boat 504 is heated using power supplies 507a and 507b connected to a support base 506. That is, in this embodiment, a vapor deposition source by resistance heating is used.
[0051]
An antenna 508 in which a conductor is wound in a spiral shape is provided on the vapor deposition boat 504. A high frequency power source 508a is connected to the antenna 508, and a high frequency is applied in a high vacuum to generate radio waves (typically microwaves). In this embodiment, the radio wave is positively charged in addition to the vaporized gas EL material 509. At this time, plasma may be generated between the antennas 508. This plasma may be formed using a rare gas such as argon gas or neon gas. At this time, since the partition wall 502 in the evaporation chamber is positively charged, EL material adhering to the partition wall 502 can be minimized.
[0052]
The scattered gas EL material 509 is stacked on the pixel electrode 511 so as to avoid the electric field formed by the control bank 510. A positive power source 512 is connected to the control bank 510, thereby forming an electric field. Although not shown, all control banks are electrically connected so as to have the same potential.
[0053]
At this time, a negative power source 514 is connected to the source wiring of the TFT 513 to which the pixel electrode 511 is connected, so that a negative voltage can be applied to the pixel electrode 511. Further, the substrate 515 having the TFT 513 is held by the susceptor 516. The susceptor 516 may be negatively charged during film formation.
[0054]
The pixel electrode 511 is negatively charged by applying a negative voltage by operating the TFT 513 electrically connected thereto. In other words, this embodiment is also characterized in that the EL material is laminated while the TFT 513 is operated. Of course, the TFT 513 is not necessarily operated.
[0055]
With the above-described configuration, it is possible to increase the utilization efficiency of the vapor EL material 509 to be deposited and to form a desired EL layer with a minimum necessary amount. Therefore, the consumption of the EL material is greatly reduced, so that the manufacturing cost can be reduced.
[0056]
In this embodiment, an electric field formed between the electrodes 508a and 508b is added to the gas EL material 509 to be positively charged. However, a bias voltage is applied between the anode 511 and the vapor deposition boat 504. It can also be positively charged.
[0057]
In this embodiment, an example in which the gas EL material is positively charged is shown, but it is also possible to negatively charge the material. In that case, the partition 502, the vapor deposition boat 504, and the control bank 510 may be negatively charged, and the anode 511 may be positively charged.
[0058]
Example 5
FIG. 6 is a cross-sectional view of the pixel portion in the light-emitting device of the present invention, FIG. 7A is a top view thereof, and FIG. 7B is a circuit configuration thereof. Actually, a plurality of pixels are arranged in a matrix to form a pixel portion (image display portion). Accordingly, since common reference numerals are used in FIGS. 6 and 7, it is preferable to refer to both drawings as appropriate. Moreover, although two pixels are illustrated in the top view of FIG. 7, both have the same structure.
[0059]
In FIG. 6, reference numeral 11 denotes a substrate, and 12 denotes an insulating film to be a base (hereinafter referred to as a base film). As the substrate 11, a substrate made of glass, glass ceramics, quartz, silicon, ceramics, metal or plastic can be used.
[0060]
The base film 12 is particularly effective when a substrate containing mobile ions or a conductive substrate is used, but it need not be provided on the quartz substrate. As the base film 12, an insulating film containing silicon may be used. In addition, it is effective to dissipate the heat generated by the TFT by providing the base film 12 with a heat dissipation effect in order to prevent the deterioration of the TFT or the EL element. Any known material can be used to provide a heat dissipation effect.
[0061]
Here, two TFTs are formed in the pixel. Reference numeral 601 denotes a switching TFT, which is an n-channel TFT, and 602 is a current control TFT, which is a p-channel TFT.
[0062]
However, in the present invention, it is not necessary to limit the switching TFT to an n-channel TFT and the current control TFT to a p-channel TFT. The switching TFT is a p-channel TFT and the current control TFT is an n-channel TFT. It is also possible to use n-channel or p-channel TFTs for both.
[0063]
The switching TFT 601 includes a source region 13, a drain region 14, LDD regions 15a to 15d, an active layer including a high concentration impurity region 16 and channel forming regions 17a and 17b, a gate insulating film 18, gate electrodes 19a and 19b, and a first interlayer. An insulating film 20, a source wiring 21, and a drain wiring 22 are formed.
[0064]
As shown in FIG. 7, the gate electrodes 19a and 19b have a double gate structure in which the gate electrodes 19a and 19b are electrically connected by a gate wiring 611 formed of another material (a material having a lower resistance than the gate electrodes 19a and 19b). ing. Of course, 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 single gate or a triple gate structure may be used. The multi-gate structure is extremely effective in reducing the off-current value. In the present invention, the switching element 601 of the pixel has a multi-gate structure, thereby realizing a switching element with a low off-current value.
[0065]
The active layer is formed of a semiconductor film including a crystal structure. That is, a single crystal semiconductor film, a polycrystalline semiconductor film, or a microcrystalline semiconductor film may be used. The gate insulating film 18 may be formed of an insulating film containing silicon. Any conductive film can be used for the gate electrode, the source wiring, or the drain wiring.
[0066]
Further, in the switching TFT 601, the LDD regions 15 a to 15 d are provided so as not to overlap the gate electrodes 19 a and 19 b with the gate insulating film 18 interposed therebetween. Such a structure is very effective in reducing the off-current value.
[0067]
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 the off-state current value. In the case of a multi-gate structure having two or more gate electrodes, a high-concentration impurity region provided between channel formation regions is effective in reducing the off-current value.
[0068]
Next, the current control TFT 602 includes an active layer including the source region 31, the drain region 32, and the channel formation region 34, the gate insulating film 18, the gate electrode 35, the first interlayer insulating film 20, the source wiring 36, and the drain wiring 37. Formed. The gate electrode 35 has a single gate structure, but may have a multi-gate structure.
[0069]
As shown in FIG. 7A, the drain of the switching TFT is connected to the gate of the current control TFT 602. Specifically, the gate electrode 35 of the current control TFT 602 is electrically connected to the drain region 14 of the switching TFT 601 through the drain wiring (also referred to as connection wiring) 22. The source wiring 36 is a current supply line and is connected to a supply source of current flowing in the EL element.
[0070]
The current control TFT 602 is an element for controlling the amount of current injected into the EL element 603, but it is not preferable to flow a large amount of current in consideration of deterioration of the EL element. Therefore, it is preferable to design the channel length (L) to be long so that an excessive current does not flow through the current control TFT 602. Desirably, it is set to 0.5 to 2 μA (preferably 1 to 1.5 μA) per pixel.
[0071]
The length (width) of the LDD region formed in the switching TFT 601 may be 0.5 to 3.5 μm, typically 2.0 to 2.5 μm.
[0072]
Further, as shown in FIG. 7A, the wiring 35 including the gate electrode of the current control TFT 602 overlaps the source wiring (current supply line) 36 of the current control TFT 602 with an insulating film interposed therebetween in the region indicated by 50. . At this time, in a region indicated by 50, a storage capacitor (capacitor) is formed. Here, a capacitor formed by the semiconductor film 51 electrically connected to the source wiring 36, an insulating film (not shown) in the same layer as the gate insulating film, and the power supply line 36 can also be used as the storage capacitor. It is.
The holding capacitor 50 functions as a capacitor for holding a voltage applied to the gate electrode 35 of the current control TFT 602.
[0073]
From the viewpoint of increasing the amount of current that can be passed, the thickness of the active layer (especially the channel formation region) of the current control TFT 602 may be increased (preferably 50 to 100 nm, more preferably 60 to 80 nm). It is valid. On the other hand, in the case of the switching TFT 601, from the viewpoint of reducing the off-current value, the thickness of the active layer (particularly the channel formation region) should be reduced (preferably 20 to 50 nm, more preferably 25 to 40 nm). Is also effective.
[0074]
In addition, when performing multi-gradation display by an analog gradation method, it is preferable to operate the current control TFT 602 in a saturation region. On the other hand, when performing multi-gradation display by the digital gradation method, it is preferable to operate the current control TFT 602 in a linear region.
[0075]
Next, reference numeral 38 denotes a 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.
[0076]
On the passivation film 38, a second interlayer insulating film (also referred to as a flattening film) 39 is formed so as to cover each TFT, and a step formed by the TFT is flattened. The second interlayer insulating film 39 is preferably an organic resin film, and polyimide, polyamide, acrylic resin, BCB (benzocyclobutene), or the like may be used. Of course, an inorganic film may be used if sufficient planarization is possible.
[0077]
It is very important to flatten the step due to the TFT by the second interlayer insulating film 39. Since an EL layer to be formed later is very thin, a light emission defect may occur due to the presence of a step. Therefore, it is desirable to planarize the pixel electrode before forming the pixel electrode so that the EL layer can be formed as flat as possible.
[0078]
Reference numeral 40 denotes a pixel electrode (corresponding to an anode of an EL element) made of a transparent conductive film, and an opening formed after a contact hole (opening) is formed in the second interlayer insulating film 39 and the passivation film 38. Are formed so as to be connected to the drain wiring 37 of the current control TFT 602.
[0079]
In this embodiment, a conductive film made of a compound of indium oxide and tin oxide is used as the pixel electrode. Further, a small amount of gallium may be added thereto. Further, a compound of indium oxide and zinc oxide or a compound of zinc oxide and gallium oxide can be used.
[0080]
When the pixel electrode is formed, a support bank 41a made of a resin film is formed, and a control bank 41b made of a metal film is formed thereon. At the same time, an insulating film (hereinafter referred to as a filling material) 42 for filling the contact hole of the pixel electrode 40 is formed. In this embodiment, the bank 41a and the filling material 42 are formed of acrylic, and the control bank 41b is formed of a tungsten film.
[0081]
At this time, the film thickness of the support bank 41a and the embedding material 42 made of acrylic is preferably 300 nm or less, preferably 100 to 200 nm, and the edge portion (end portion) is preferably tapered. The control bank 41b made of a tungsten film is also preferably formed so that the edge portion has a tapered shape.
[0082]
The support bank 41a and the control bank 41b are formed so as to surround the end portion of the pixel electrode 40 as shown in FIG.
[0083]
Next, the EL layer 43 is formed by the film forming method described with reference to FIGS. Although only one pixel is shown here, EL layers corresponding to each color of R (red), G (green), and B (blue) are formed. In this embodiment, the vapor deposition method shown in FIG. 2 is employed, and a low molecular EL material is used as the EL material.
[0084]
In this embodiment, as the EL material, a red light emitting EL layer doped with red fluorescent dye DCM using Alq as a host material is used. In addition, the EL layer for green light emission has Alq which is an 8-hydroxyquinoline complex of aluminum. _Three In the EL layer for blue light emission, a zinc benzoxazole complex (Zn (oxz)) is used. ₂ ) Is used.
[0085]
However, the above example is an example of an EL material that can be used as the EL layer of the present invention, and is not necessarily limited to this. That is, a high molecular EL material not described here can be used, and a high molecular EL material and a low molecular EL material may be used in combination.
[0086]
After the EL layer 43 is formed as described above, an alloy film obtained by adding lithium to aluminum is used as the cathode 44 in this embodiment in which the cathode 44 made of a metal film is formed next. Although not shown, an insulating film can be formed on the cathode 44 as a passivation film.
[0087]
Thus, an EL element 603 including the pixel electrode 40, the EL layer 43, and the cathode 44 is formed. In practice, after the EL element 603 is formed, a cover material is provided on the EL element 603 and sealed in an inert atmosphere, or a resin is provided on the entire surface and sealed so that the EL element does not come into contact with outside air. Is desirable.
[0088]
It is also effective to provide a dehumidifying agent (typically barium oxide) or an antioxidant in the sealed space or resin.
[0089]
Any of the configurations of Examples 1 to 4 can be used in manufacturing the light emitting device of this example.
[0090]
Example 6
In this embodiment, a method for simultaneously manufacturing a pixel portion and a TFT of a driver circuit portion provided around the pixel portion will be described with reference to FIGS. However, in order to simplify the description, a CMOS circuit, which is a basic circuit, is illustrated with respect to the drive circuit.
[0091]
First, as shown in FIG. 8A, a base film 801 is formed to a thickness of 300 nm over a glass substrate 800. In this embodiment, a 100 nm thick silicon nitride oxide film and a 200 nm silicon nitride oxide film are stacked as the base film 801. At this time, the nitrogen concentration in contact with the glass substrate 800 is preferably 10 to 25 wt%. Of course, the element may be formed directly on the quartz substrate without providing a base film.
[0092]
Next, an amorphous silicon film (not shown) having a thickness of 50 nm is formed on the base film 801 by a known film formation method. Note that the semiconductor film is not limited to an amorphous silicon film, and any semiconductor film including an amorphous structure (including a microcrystalline semiconductor film) may be used. Further, a compound semiconductor film including an amorphous structure such as an amorphous silicon germanium film may be used. The film thickness may be 20 to 100 nm.
[0093]
Then, the amorphous silicon film is crystallized by a known technique to form a crystalline silicon film (also referred to as a polycrystalline silicon film or a polysilicon film) 802. Known crystallization methods include a thermal crystallization method using an electric furnace, a laser annealing crystallization method using laser light, and a lamp annealing crystallization method using infrared light. In this embodiment, crystallization is performed using excimer laser light using XeCl gas.
[0094]
In this embodiment, a pulse oscillation type excimer laser beam processed into a linear shape is used. However, a rectangular shape, a continuous oscillation type argon laser beam, or a continuous oscillation type excimer laser beam may be used. .
[0095]
In this embodiment, a crystalline silicon film is used as an active layer of a TFT, but an amorphous silicon film can also be used. It is also possible to form the active layer of the switching TFT that needs to reduce the off-current with an amorphous silicon film and form the active layer of the current control TFT with a crystalline silicon film. Since the amorphous silicon film has low carrier mobility, it is difficult for an electric current to flow and an off current is difficult to flow. That is, the advantages of both an amorphous silicon film that hardly allows current to flow and a crystalline silicon film that easily allows current to flow can be utilized.
[0096]
Next, as shown in FIG. 8B, a protective film 803 made of a silicon oxide film is formed on the crystalline silicon film 802 to a thickness of 130 nm. This thickness may be selected in the range of 100 to 200 nm (preferably 130 to 170 nm). Any other film may be used as long as it is an insulating film containing silicon. This protective film 803 is provided to prevent the crystalline silicon film from being directly exposed to plasma when impurities are added, and to enable fine concentration control.
[0097]
Then, resist masks 804a and 804b are formed thereon, and an impurity element imparting n-type (hereinafter referred to as an n-type impurity element) is added through the protective film 803. Note that as the n-type impurity element, an element typically belonging to Group 15, typically phosphorus or arsenic can be used. In this example, phosphine (PH _Three ) Using a plasma (ion) doping method in which plasma is excited without mass separation, and phosphorus is 1 × 10 ¹⁸ atoms / cm ^Three Add at a concentration of Of course, an ion implantation method for performing mass separation may be used.
[0098]
In the n-type impurity region 805 formed by this step, an n-type impurity element is 2 × 10 6. ¹⁶ ~ 5x10 ¹⁹ atoms / cm ^Three (Typically 5 × 10 ¹⁷ ~ 5x10 ¹⁸ atoms / cm ^Three ) Adjust the dose so that it is included at the concentration of
[0099]
Next, as shown in FIG. 8C, the protective film 803 and the resists 804a and 804b are removed, and the added elements belonging to Group 15 are activated. As the activation means, a known technique may be used. In this embodiment, activation is performed by irradiation with excimer laser light. Of course, the pulse oscillation type or the continuous oscillation type may be used, and it is not necessary to limit to the excimer laser beam. However, since the purpose is to activate the added impurity element, it is preferable to irradiate with energy that does not melt the crystalline silicon film. Note that laser light may be irradiated while the protective film 803 is attached.
[0100]
Note that activation by heat treatment may be used in combination with the activation of the impurity element by the laser beam. When activation by heat treatment is performed, heat treatment at about 450 to 550 ° C. may be performed in consideration of the heat resistance of the substrate.
[0101]
By this step, an end portion of the n-type impurity region 805, that is, a boundary portion (junction portion) between the n-type impurity region 805 and a region not added with the n-type impurity element is clarified. This means that when the TFT is later completed, the LDD region and the channel formation region can form a very good junction.
[0102]
Next, as shown in FIG. 8D, unnecessary portions of the crystalline silicon film are removed, and island-shaped semiconductor films (hereinafter referred to as active layers) 806 to 809 are formed.
[0103]
Next, as illustrated in FIG. 8E, a gate insulating film 810 is formed so as to cover the active layers 806 to 809. As the gate insulating film 810, an insulating film containing silicon with a thickness of 10 to 200 nm, preferably 50 to 150 nm may be used. This may be a single layer structure or a laminated structure. In this embodiment, a silicon nitride oxide film having a thickness of 110 nm is used.
[0104]
Next, a conductive film having a thickness of 200 to 400 nm is formed and patterned to form gate electrodes 811 to 815. The ends of the gate electrodes 811 to 815 can be tapered. Note that in this embodiment, the gate electrode and a wiring (hereinafter referred to as a gate wiring) electrically connected to the gate electrode are formed using different materials. Specifically, a material having a resistance lower than that of the gate electrode is used for the gate wiring. This is because a material that can be finely processed is used for the gate electrode, and a material that has a low wiring resistance is used for the gate wiring even though it cannot be finely processed. Of course, the gate electrode and the gate wiring may be formed of the same material.
[0105]
The gate electrode may be formed of a single-layer conductive film, but it is preferable to form a stacked film of two layers or three layers as necessary. Any known conductive film can be used as the material of the gate electrode. However, a material that can be finely processed as described above, specifically, that can be patterned to a line width of 2 μm or less is preferable.
[0106]
Typically, a film made of an element selected from tantalum (Ta), titanium (Ti), molybdenum (Mo), tungsten (W), chromium (Cr), and silicon (Si), or a nitride film of the element (Typically a tantalum nitride film, a tungsten nitride film, a titanium nitride film), an alloy film (typically, a Mo—W alloy, a Mo—Ta alloy), or a silicide film of the above elements (typical) Specifically, a tungsten silicide film or a titanium silicide film) can be used. Of course, it may be used as a single layer or may be laminated.
[0107]
In this embodiment, a laminated film including a tantalum nitride (TaN) film having a thickness of 50 nm and a tungsten (W) film having a thickness of 350 nm is used. This may be formed by sputtering. Further, when an inert gas such as Xe or Ne is added as a sputtering gas, peeling of the film due to stress can be prevented.
[0108]
At this time, the gate electrode 812 is formed so as to overlap with part of the n-type impurity region 805 with the gate insulating film 810 interposed therebetween. This overlapped portion later becomes an LDD region overlapping with the gate electrode. Note that the gate electrodes 813 and 814 appear to be two in the cross section, but are actually electrically connected.
[0109]
Next, as shown in FIG. 9A, an n-type impurity element (phosphorus in this embodiment) is added in a self-aligning manner using the gate electrodes 811 to 815 as a mask. The impurity regions 816 to 823 thus formed are adjusted so that phosphorus is added at a concentration of 1/2 to 1/10 (typically 1/3 to 1/4) of the n-type impurity region 805. Specifically, 1 × 10 ¹⁶ ~ 5x10 ¹⁸ atoms / cm ^Three (Typically 3x10 ¹⁷ ~ 3x10 ¹⁸ atoms / cm ^Three ) Is preferred.
[0110]
Next, as shown in FIG. 9B, resist masks 824a to 824d are formed so as to cover the gate electrodes and the like, and an n-type impurity element (phosphorus in this embodiment) is added to contain phosphorus at a high concentration. Impurity regions 825 to 829 are formed. Again, phosphine (PH _Three The concentration of phosphorus in this region is 1 × 10 ²⁰ ~ 1x10 ^{twenty one} atoms / cm ^Three (Typically 2 × 10 ²⁰ ~ 5x10 ²⁰ atoms / cm ^Three ).
[0111]
Although the source region or drain region of the n-channel TFT is formed by this process, the switching TFT leaves a part of the n-type impurity regions 819 to 821 formed in the process of FIG. This remaining region corresponds to the LDD regions 15a to 15d of the switching TFT 601 in FIG.
[0112]
Next, as shown in FIG. 9C, the resist masks 824a to 824d are removed, and a new resist mask 832 is formed. Then, a p-type impurity element (boron in this embodiment) is added to form impurity regions 833 to 836 containing boron at a high concentration. Here, diborane (B ₂ H ₆ 3 × 10 by ion doping method using ²⁰ ~ 3x10 ^{twenty one} atoms / cm ^Three (Typically 5 × 10 ²⁰ ~ 1x10 ^{twenty one} atoms / cm ^Three Boron is added so that the concentration of
[0113]
Note that the impurity regions 833 to 836 already have 1 × 10 6. ²⁰ ~ 1x10 ^{twenty one} atoms / cm ^Three However, the boron added here is added at a concentration at least three times that of phosphorus. Therefore, the n-type impurity region formed in advance is completely inverted to the p-type and functions as a p-type impurity region.
[0114]
Next, after removing the resist mask 832, the n-type or p-type impurity element added at each concentration is activated. As the activation means, furnace annealing, laser annealing, or lamp annealing can be used. In this embodiment, heat treatment is performed in an electric furnace in a nitrogen atmosphere at 550 ° C. for 4 hours.
[0115]
At this time, it is important to eliminate oxygen in the atmosphere as much as possible. This is because the presence of even a small amount of oxygen oxidizes the exposed surface of the gate electrode, which increases resistance and makes it difficult to make ohmic contact later. Therefore, the oxygen concentration in the treatment atmosphere in the activation step is 1 ppm or less, preferably 0.1 ppm or less.
[0116]
Next, when the activation process is completed, a gate wiring 837 having a thickness of 300 nm is formed as shown in FIG. As a material of the gate wiring 837, a metal containing aluminum (Al) or copper (Cu) as a main component (occupying 50 to 100% as a composition) may be used. As shown in FIG. 7, the gate wiring 611 and the gate electrodes 19a and 19b of the switching TFT (813 and 814 in FIG. 8E) are electrically connected as shown in FIG.
[0117]
With such a structure, the wiring resistance of the gate wiring can be extremely reduced, so that an image display region (pixel portion) having a large area can be formed. That is, the pixel structure of this embodiment is extremely effective in realizing a light emitting device having a screen size of 10 inches or more (or 30 inches or more) diagonally.
[0118]
Next, as shown in FIG. 10A, a first interlayer insulating film 838 is formed. As the first interlayer insulating film 838, an insulating film containing silicon may be used as a single layer, or a stacked film in which two or more kinds of insulating films containing silicon are combined may be used. The film thickness may be 400 nm to 1.5 μm. In this embodiment, a structure is formed in which a silicon oxide film having a thickness of 800 nm is stacked on a silicon nitride oxide film having a thickness of 200 nm.
[0119]
Further, a hydrogenation treatment is performed by performing a heat treatment at 300 to 450 ° C. for 1 to 12 hours in an atmosphere containing 3 to 100% hydrogen. This step is a step in which the dangling bonds of the semiconductor film are terminated with hydrogen by thermally excited hydrogen. As another means for hydrogenation, plasma hydrogenation (using hydrogen generated by plasmatization) may be performed.
[0120]
Note that the hydrogenation treatment may be performed while the first interlayer insulating film 838 is formed. That is, a hydrogenation treatment may be performed as described above after a 200 nm thick silicon nitride oxide film is formed, and then the remaining 800 nm thick silicon oxide film may be formed.
[0121]
Next, contact holes are formed in the first interlayer insulating film 838 and the gate insulating film 810, and source wirings 839 to 842 and drain wirings 843 to 845 are formed. In this embodiment, this electrode is a laminated film having a three-layer structure in which a Ti film is 100 nm, an aluminum film containing Ti is 300 nm, and a Ti film 150 nm is continuously formed by sputtering. Of course, other conductive films may be used.
[0122]
Next, a passivation film 846 is formed with a thickness of 50 to 500 nm (typically 200 to 300 nm). In this embodiment, a silicon nitride oxide film having a thickness of 300 nm is used as the first passivation film 846. This may be replaced by a silicon nitride film.
[0123]
Prior to the formation of the silicon nitride oxide film, H ₂ , NH _Three It is effective to perform plasma treatment using a gas containing isohydrogen. Hydrogen excited by this pretreatment is supplied to the first interlayer insulating film 838 and heat treatment is performed, whereby the film quality of the passivation film 846 is improved. At the same time, hydrogen added to the first interlayer insulating film 838 diffuses to the lower layer side, so that the active layer can be effectively hydrogenated.
[0124]
Next, as shown in FIG. 10B, a second interlayer insulating film 847 made of an organic resin is formed. As the organic resin, polyimide, polyamide, acrylic resin, BCB (benzocyclobutene), or the like can be used. In particular, since the second interlayer insulating film 847 has a strong meaning of flattening, an acrylic resin excellent in flatness is preferable. In this embodiment, the acrylic resin film is formed with a film thickness that can sufficiently flatten the step formed by the TFT. The thickness is preferably 1 to 5 μm (more preferably 2 to 4 μm).
[0125]
Next, contact holes are formed in the second interlayer insulating film 847 and the passivation film 846, and a pixel electrode 848 that is electrically connected to the drain wiring 845 is formed. In this embodiment, an indium tin oxide (ITO) film having a thickness of 110 nm is formed and patterned to form a pixel electrode. Alternatively, a compound in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide, or a compound made of zinc oxide and gallium oxide may be used as the transparent electrode. This pixel electrode becomes the anode of the EL element.
[0126]
Next, as shown in FIG. 10C, a support bank 849a made of resin and a filling material 850 are formed. These are etched after forming a 500 nm acrylic film to a thickness of 200 nm, and patterned to a shape as shown in FIG.
[0127]
Further, a control bank 849b made of a metal film is formed on the support bank 849a. In this embodiment, a tungsten film is used as the metal film, and a taper shape is formed at the time of etching. The technology for forming the taper may be referred to Japanese Patent Application No. 11-206954 filed by the present applicant.
[0128]
Next, the EL layer 851 is formed by the method shown in FIGS. Although only one pixel is shown here, EL layers corresponding to each color of R (red), G (green), and B (blue) are formed. In this embodiment, as the EL material, the EL layer for red light emission has Alq. _Three Is used as a host material doped with a red fluorescent dye DCM. In addition, the EL layer for green light emission has Alq which is an 8-hydroxyquinoline complex of aluminum. _Three In the EL layer for blue light emission, a zinc benzoxazole complex (Zn (oxz)) is used. ₂ ) And each having a thickness of 50 nm.
[0129]
Note that although the EL layer 851 has a single layer structure in this embodiment, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, an electron blocking layer, or a hole element layer is provided as necessary. Also good.
[0130]
After the EL layer 851 is formed, a cathode 852 made of an alloy film of aluminum and lithium is formed using a vacuum evaporation method. Note that the EL layer 851 may have a thickness of 30 to 100 nm (typically 50 to 80 nm), and the cathode 852 may have a thickness of 150 to 300 nm (typically 200 to 250 nm). In this embodiment, an example in which an alloy film of aluminum and lithium is used as the cathode 852 of the EL element is shown, but other known materials may be used.
[0131]
Here, FIG. 11 shows a cross-sectional structure when an n-channel TFT is used as the switching TFT. First, in FIG. 11A, the LDD regions 15a to 15d are provided so as not to overlap the date electrodes 19a and 19b with the gate insulating film 18 interposed therebetween. Such a structure is very effective in reducing the off-current value.
[0132]
On the other hand, these LDD regions 15a to 15d are not provided in FIG. In the case of the structure shown in FIG. 11B, the number of steps can be reduced as compared with the case where the structure shown in FIG. 11A is formed, so that the production efficiency can be improved.
[0133]
In the present invention, any of the structures shown in FIGS. 11A and 11B may be used as the switching TFT.
[0134]
Next, FIG. 12 shows a cross-sectional structure when an n-channel TFT is used as the current control TFT. First, in the current control TFT shown in FIG. 12A, an LDD region 33 is provided between the drain region 32 and the channel formation region 34. Here, a structure in which the LDD region 33 has a region that overlaps with the gate electrode 35 with the gate insulating film 18 interposed therebetween and a region that does not overlap with the gate electrode 35 are shown, but the LDD region 33 is provided as shown in FIG. It is good also as a structure without.
[0135]
The current control TFT supplies a current for causing the EL element to emit light, and at the same time controls the supply amount to enable gradation display. Therefore, it is necessary to take measures against deterioration by hot carrier injection so that it does not deteriorate even when current is passed.
[0136]
Regarding deterioration due to hot carrier injection, it is known that a structure in which an LDD region overlaps a gate electrode is very effective. Therefore, as shown in FIG. 12A, a structure in which an LDD region is provided in a region overlapping the gate electrode 35 with the gate insulating film 18 interposed therebetween is appropriate. A structure in which an LDD region that does not have to be provided is also shown. However, the LDD region that does not overlap with the gate electrode is not necessarily provided.
[0137]
Further, when the voltage applied between the source region and the drain region of the current control TFT is 10 V or less, preferably 5 V or less, the hot carrier deterioration does not become a problem. Therefore, as shown in FIG. It is not necessary to provide an area.
[0138]
In this embodiment, as shown in FIG. 10C, the active layer of the n-channel type 605 includes a source region 855, a drain region 856, an LDD region 857, and a channel formation region 858. It overlaps with the gate electrode 812 with the gate insulating film 810 interposed therebetween.
[0139]
The reason why the LDD region is formed only on the drain region side is to prevent the operation speed from being lowered. Further, the n-channel TFT 605 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 857 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.
[0140]
Thus, an active matrix substrate having a structure as shown in FIG. 10C is completed. In the active matrix substrate of this embodiment, the TFT having the optimum structure is arranged not only in the pixel portion but also in the driving circuit portion, so that it can show very high reliability and improve the operating characteristics.
[0141]
First, a TFT having a structure that reduces hot carrier injection so as not to reduce the operating speed as much as possible is used as an n-channel TFT 605 of a CMOS circuit that forms a driver circuit portion. Note that the drive circuit here includes a shift register, a buffer, a level shifter, a sampling circuit (sample and hold circuit), and the like. In the case of performing digital driving, a signal conversion circuit such as a D / A converter may be included.
[0142]
Actually, after completion of FIG. 10C, it is preferable to package (enclose) with a cover material such as highly airtight glass, quartz, or plastic so as not to be exposed to the outside air. At that time, a hygroscopic agent such as barium oxide or an antioxidant may be disposed inside the cover material.
[0143]
In addition, if the airtightness is improved by processing such as packaging, a connector (flexible printed circuit: FPC) for connecting the terminal drawn from the element or circuit formed on the insulator and the external signal terminal is attached. Completed as a product. In this specification, such a state that can be shipped is referred to as an EL display device (or EL module).
[0144]
Note that a driver circuit for transmitting a signal to the pixel portion, another memory, a control circuit, a power supply circuit, or the like may be provided using an IC using single crystal silicon. In that case, the IC may be connected using TAB or COG, and an IC mounted on a printed wiring board may be connected using a TAB tape.
[0145]
Here, the structure of the light emitting device of this embodiment will be described with reference to the perspective view of FIG. The light emitting device of this embodiment includes a pixel portion 1302, a gate side driver circuit 1303, and a source side driver circuit 1304 which are formed on a glass substrate 1301. The switching TFT 1305 in the pixel portion is an n-channel TFT and is arranged at the intersection of a gate wiring 1306 connected to the gate side driver circuit 1303 and a source wiring 1307 connected to the source side driver circuit 1304. The drain of the switching TFT 1305 is connected to the gate of the current control TFT 1308.
[0146]
Further, the source side of the current control TFT 1308 is connected to the current supply line 1309. An EL element 1310 is connected to the drain of the current control TFT 1308. A predetermined voltage is applied to the cathode of the EL element 1310.
[0147]
The FPC 1311 serving as an external input / output terminal is provided with connection wirings 1312 and 1313 for transmitting signals to the drive circuit portion and a connection wiring 1314 connected to the current supply line 1309.
[0148]
FIG. 14 illustrates an example of a circuit configuration of the light-emitting device illustrated in FIG. The light-emitting device of this embodiment includes a source side driver circuit 1401, a gate side driver circuit (A) 1407, a gate side driver circuit (B) 1411, and a pixel portion 1406. Note that in this specification, the drive circuit portion is a generic term including a source side processing circuit and a gate side drive circuit.
[0149]
The source side driver circuit 1401 includes a shift register 1402, a level shifter 1403, a buffer 1404, and a sampling circuit (transfer gate) 1405. The gate side driver circuit (A) 1407 includes a shift register 1408, a level shifter 1409, and a buffer 1410. The gate side driver circuit (B) 1411 has a similar structure.
[0150]
Here, the shift registers 1402 and 1408 have a driving voltage of 5 to 16 V (typically 10 V), and an n-channel TFT used in a CMOS circuit forming the circuit has a structure indicated by 605 in FIG. Is suitable.
[0151]
As the level shifters 1403 and 1409 and the buffers 1404 and 1410, a CMOS circuit including the n-channel TFT 605 in FIG. In addition, it is effective in improving the reliability of each circuit that the gate wiring has a multi-gate structure such as a double gate structure or a triple gate structure.
[0152]
The pixel portion 1406 is provided with pixels having the structure shown in FIG.
[0153]
Note that the above configuration can be easily realized by manufacturing a TFT according to the manufacturing steps shown in FIGS. Further, in this embodiment, only the configuration of the pixel portion and the drive circuit portion is shown. However, according to the manufacturing process of this embodiment, a signal dividing circuit, a D / A converter circuit, an operational amplifier circuit, a γ correction circuit, etc. It is considered that logic circuits other than the drive circuit can be formed on the same insulator, and further, a memory portion, a microprocessor, and the like can be formed.
[0154]
Further, the EL module of this embodiment including the cover material will be described with reference to FIGS. Note that the reference numerals used in FIGS. 13 and 14 are cited as necessary.
[0155]
FIG. 15A is a top view showing a state in which a sealing structure is provided in the state shown in FIG. 1302 indicated by a dotted line is a pixel portion, 1303 is a gate side driver circuit, and 1304 is a source side driver circuit. The sealing structure of the present invention is a structure in which a filler (not shown), a cover material 1501, a seal material (not shown), and a frame material 1502 are provided in the state of FIG.
[0156]
Here, FIG. 15B is a cross-sectional view taken along line AA ′ of FIG. In FIGS. 15A and 15B, the same reference numerals are used for the same parts.
[0157]
As shown in FIG. 15B, a pixel portion 1302 and a gate side driver circuit 1303 are formed over a substrate 1301, and the pixel portion 1302 includes a current control TFT 602 and a pixel electrode 848 electrically connected thereto. A plurality of pixels are included. The gate side driver circuit 1303 is formed using a CMOS circuit in which an n-channel TFT 605 and a p-channel TFT 606 are complementarily combined.
[0158]
The pixel electrode 848 functions as an anode of the EL element. A support bank 849a and a control bank 849b are formed in the gap between the pixel electrodes 848, and an EL layer 851 and a cathode 852 are formed inside the support bank 849a and the control bank 849b. Of course, the EL element structure may be reversed and the pixel electrode may be a cathode.
[0159]
In this embodiment, the cathode 852 also functions as a common wiring for each pixel column, and is electrically connected to the FPC 1311 via the connection wiring 1312.
[0160]
Next, a filler 1503 is provided so as to cover the EL element. This filler 1503 also functions as an adhesive for bonding the cover material 1501. As the filler 1503, PVC (polyvinyl chloride), epoxy resin, silicone resin, PVB (polyvinyl butyral), or EVA (ethylene vinyl acetate) can be used. It is preferable to provide a desiccant (not shown) inside the filler 1503 because the moisture absorption effect can be maintained. At this time, the desiccant may be added to the filler, or may be sealed in the filler.
[0161]
In this embodiment, as the cover material 1501, a material made of glass, plastic, and ceramics can be used. Note that it is effective to add a moisture absorbent such as barium oxide in the interior of the filler 1503 in advance.
[0162]
Next, after adhering the cover material 1501 using the filler 1503, the frame material 1502 is attached so as to cover the side surface (exposed surface) of the filler 1503. The frame material 1502 is bonded by a seal material (functioning as an adhesive) 1504. At this time, a photocurable resin is preferably used as the sealant 1504, but a thermosetting resin may be used if the heat resistance of the EL layer permits. Note that the sealant 1504 is desirably a material that does not transmit moisture and oxygen as much as possible. Further, a desiccant may be added to the inside of the sealing material 1504.
[0163]
By encapsulating the EL element in the filler 1503 using the above-described method, the EL element can be completely blocked from the outside, and a substance that promotes deterioration due to oxidation of the EL layer such as moisture or oxygen from the outside can be obtained. Intrusion can be prevented. Accordingly, a highly reliable EL display device can be manufactured.
[0164]
Further, a polarizing plate may be provided on the display surface (the surface on which an image is observed) of the light emitting device described in this embodiment. This polarizing plate has an effect of suppressing reflection of light incident from the outside and preventing an observer from being reflected on the display surface. Generally, a circularly polarizing plate is used. However, in order to prevent the light emitted from the EL layer from being reflected by the polarizing plate and returned to the inside, it is desirable to adjust the refractive index so that the structure has less internal reflection.
[0165]
Example 7
In Examples 1 to 6, the case where the anode, the EL layer, and the cathode are stacked in this order on the insulator has been mainly described. However, it is also possible to stack the cathode, the EL layer, the anode, and the auxiliary wiring in this order. It is.
[0166]
The former observes light that has passed through the insulator, whereas the latter emits light in a direction away from the insulator.
[0167]
Example 8
In this embodiment, an example will be described in which the present invention is implemented when a plurality of light emitting devices are manufactured from one substrate by multi-cavity. FIG. 16 is used for the description.
[0168]
A plurality of light-emitting devices including a pixel portion 1602a and a drive circuit 1602b are formed over the glass substrate 1601. In this embodiment, nine light emitting devices are formed on one glass substrate. The pixel portion 1602a of each light emitting device has a structure as shown in FIG. 1, and a control bank 1603 is formed in each pixel portion 1602a in a matrix.
[0169]
In this embodiment, wirings (hereinafter referred to as bank connection wirings) 1604 for connecting individual control banks are formed so that all the control banks 1603 have the same potential, and if a voltage is applied to the pad portion 1605, the voltage is applied. Everything is transmitted to the anode. The bank connection wiring 1604 is characterized in that it is used for countermeasures against static electricity. That is, if all have the same potential, no suddenly large voltage is applied between the wirings, so that dielectric breakdown or the like can be effectively suppressed.
[0170]
Here, FIG. 17A shows an enlarged view of a region 1600 surrounded by a dotted line. As shown in FIG. 17A, the bank connection wiring 1604 is formed at the same time as the control bank 1603 and has a portion connected by a buffer wiring 1606 in the middle. The buffer wiring 1606 is formed using an oxide conductive film simultaneously with the pixel electrode (in this embodiment, the anode of the EL element).
[0171]
Here, a cross-sectional view taken along line AA ′ of FIG. 17A is shown in FIG. Reference numeral 1607 denotes an interlayer insulating film stacked in the process of manufacturing a TFT.
[0172]
Since the oxide conductive film used as the buffer wiring 1606 has a higher resistance value than the metal film, the buffer wiring functions as a kind of resistor. Therefore, even if a large current flows through the bank connection wiring 1604, it is buffered by the buffer wiring, and damage to a plurality of light emitting devices can be prevented.
[0173]
By adopting the structure of this embodiment as described above, the present invention can be implemented without providing complicated wiring even when a plurality of light emitting devices are manufactured at once by a multi-cavity process.
[0174]
Further, when the light-emitting device is completed, the substrate 1601 may be divided using a dicer or a scriber to separate the light-emitting devices individually. At this time, if the bank connection wiring 1604 is also divided, each light emitting device is electrically isolated. In addition, the structure of a present Example can be implemented in combination with any structure of Examples 1-7 freely.
[0175]
Example 9
In this embodiment, a case where the present invention is used in combination with a shadow mask will be described. FIG. 18 is used for the description. In addition, the same part as the structure shown in FIG. 2 is demonstrated using the same code | symbol.
[0176]
In FIG. 18, a shadow mask 1801 is further provided above the control bank 105b, and the shadow mask 1801 is negatively charged. That is, the shadow mask 1801 and the control bank 105b are charged with the same polarity.
[0177]
At this time, the distance between the control banks 105b is set to X ₁ And the distance of the opening provided in the shadow mask 1801 is X ₂ X ₁ <X ₂ It is preferable to have the relationship. In this manner, the EL material (or the solution containing the EL material) 201 flying from above the shadow mask 1801 is first guided to the vicinity of the opening of the shadow mask 1801 by the electric field formed by the shadow mask 1801. Further, it is guided into the pixel by the electric field formed by the control bank 105b. Thus, the EL layer 202 is formed.
[0178]
The structure of this example is that different types of EL materials are divided into a plurality of times, particularly when the EL material for red light emission, the EL material for green light emission, and the EL material for blue light emission are separately formed. This is effective when forming a film.
[0179]
In addition, the structure of a present Example can be implemented in combination with any structure of Examples 1-8 freely.
[0180]
Example 10
In this embodiment, a case where an EL material for red light emission, an EL material for green light emission, and an EL material for blue light emission are separately formed by electric field control of the present invention without using a shadow mask will be described.
[0181]
The concept of this example is shown in FIGS. 19 (A) and 19 (B). 19A and 19B, pixel electrodes 1901 to 1903 are formed on an insulator (not shown) (an interlayer insulating film formed on a TFT in the present invention), and processed into a matrix so as to surround them. A control bank 1904 is formed.
[0182]
In this embodiment, as shown in FIG. 19A, only the pixel electrode 1902 is positively charged and the other pixel electrodes 1901 and 1903 are negatively charged. Further, the control bank 1904 is negatively charged, and in this state, the negatively charged EL material for red light emission is formed by vapor deposition. At this time, the EL material is repelled on the negatively charged pixel electrodes 1901 and 1903, and most of the film is formed on the positively charged anode 1902. Thus, an EL layer 1905 for red light emission is formed.
[0183]
Next, as shown in FIG. 19B, only the pixel electrode 1901 is positively charged, and the other anodes 1902 and 1903 are negatively charged. Further, the control bank 1904 is negatively charged, and in this state, the negatively charged green light emitting EL material is formed by vapor deposition. At this time, the EL material is repelled on the negatively charged pixel electrodes 1902 and 1903, and most of the EL material is formed on the positively charged pixel electrode 1901. Thus, an EL layer 1906 for green light emission is formed.
[0184]
Further, although not shown, in the EL layer for blue light emission, only the pixel electrode 1903 may be charged positively and the other anodes 1901 and 1902 may be negatively charged to form a blue light emitting EL material.
[0185]
In the structure of this embodiment, the trajectory of the EL material is determined by the electric field formed by the control bank 1904 and the electric field formed by the pixel electrodes 1901 to 1903, and selective film formation is possible without using a shadow mask. It is.
[0186]
In addition, the structure of a present Example can be implemented in combination with any structure of Examples 1-8 freely.
[0187]
Example 11
In the present invention, by using an EL material that can use phosphorescence from triplet excitons for light emission, the external light emission quantum efficiency can be dramatically improved. This makes it possible to reduce the power consumption, extend the life, and reduce the weight of the EL element.
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.)
The molecular formula of the EL material (coumarin dye) reported in the above paper is shown below.
[0188]
[Chemical 1]

[0189]
(MABaldo, DFO'Brien, Y.You, A.Shoustikov, S.Sibley, METhompson, SRForrest, Nature 395 (1998) p.151.)
The molecular formula of the EL material (Pt complex) reported in the above paper is shown below.
[0190]
[Chemical 2]

[0191]
(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.)
The molecular formula of the EL material (Ir complex) reported in the above paper is shown below.
[0192]
[Chemical 3]

[0193]
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. In addition, the structure of a present Example can be implemented in combination with any structure of Example 1- Example 9 freely.
[0194]
Example 12
A light-emitting device formed by implementing the present invention is a self-luminous type, so that it has excellent visibility in a bright place as compared with a liquid crystal display device and has a wide viewing angle. Therefore, it can be used as a display unit of various electric appliances. At that time, although the light-emitting device of the present invention is a passive light-emitting device, the screen can be enlarged by reducing the wiring resistance, so that the usage can be widened.
[0195]
As an electric appliance of the present invention, a video camera, a digital camera, a goggle type display (head mounted display), a car navigation system, a car audio, a notebook personal computer, a game machine, a portable information terminal (mobile computer, cellular phone, portable type) A game machine or electronic book), an image playback device equipped with a recording medium (specifically, a compact disk (CD), laser disk (LD), digital versatile disk (DVD), etc.) And a device equipped with a display that can be used. Specific examples of these electric appliances are shown in FIGS.
[0196]
FIG. 20A illustrates an EL display which includes a housing 2001, a support base 2002, and a display portion 2003. The light emitting device of the present invention can be used for the display portion 2003. Since the EL display is a self-luminous type, a backlight is not necessary, and a display portion thinner than a liquid crystal display can be obtained. Note that in the case where a stick driver is provided in the light-emitting device used for the display portion 2003, it is preferable to divide it into several tens.
[0197]
FIG. 20B illustrates a video camera, which includes a main body 2101, a display portion 2102, an audio input portion 2103, operation switches 2104, a battery 2105, and an image receiving portion 2106. The light emitting device of the present invention can be used for the display portion 2102. Note that in the case where a stick driver is provided for the light-emitting device used for the display portion 2102, it is preferable to divide the stick driver into several pieces.
[0198]
FIG. 20C illustrates a digital camera, which includes a main body 2201, a display portion 2202, an eyepiece portion 2203, and operation switches 2204. The light emitting device of the present invention can be used for the display portion 2202. Note that in the case where a stick driver is provided in the light-emitting device used for the display portion 2202, it is preferable that the light driver be divided into several pieces.
[0199]
FIG. 20D shows an image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 2301, a recording medium (CD, LD, DVD, etc.) 2302, an operation switch 2303, and a display unit (a). 2304 and a display unit (b) 2305. The display unit (a) mainly displays image information, and the display unit (b) mainly displays character information. The light emitting device of the present invention can be used for these display units (a) and (b). Note that the image reproducing device provided with the recording medium may include a CD reproducing device, a game machine, and the like. Note that in the case where a stick driver is provided in the light-emitting device used for the display portion (a) 2304 and the display portion (b) 2305, it is preferable to divide the stick driver into several tens.
[0200]
FIG. 20E illustrates a portable (mobile) computer, which includes a main body 2401, a display portion 2402, an image receiving portion 2403, operation switches 2404, and a memory slot 2405. The electro-optical device of the present invention can be used for the display portion 2402. This portable computer can record information on a recording medium in which a flash memory or a non-volatile memory is integrated, and can reproduce the information. Note that in the case where a stick driver is provided in the light-emitting device used for the display portion 2402, it is preferable to divide it into several pieces.
[0201]
FIG. 20F illustrates a personal computer, which includes a main body 2501, a housing 2502, a display portion 2503, and a keyboard 2504. The light emitting device of the present invention can be used for the display portion 2503. Note that in the case where a stick driver is provided for the light-emitting device used for the display portion 2503, it is preferable to divide the light driver into several tens.
[0202]
If the emission brightness of the EL material is increased in the future, it is possible to enlarge and project the light including the output image information with a lens or the like and use it for a front type or rear type projector.
[0203]
In addition, the electronic devices often display information distributed through an electronic communication line such as the Internet or CATV (cable television), and in particular, opportunities for displaying moving image information are increasing. Since the response speed of the EL material is very high, it is suitable for displaying such a moving image.
[0204]
In addition, since the light emitting device consumes power in the light emitting portion, it is desirable to display information so that the light emitting portion 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 car audio, it is driven so that character information is formed by the light emitting part with a non-light emitting part as a background. It is desirable.
[0205]
Here, FIG. 21A shows a mobile phone, which includes a main body 2601, an audio output portion 2602, an audio input portion 2603, a display portion 2604, operation switches 2605, and an antenna 2606. The light-emitting device of the present invention can be used for the display portion 2604. Note that the display portion 2604 can suppress power consumption of the mobile phone by displaying white characters on a black background.
[0206]
FIG. 21B shows a car audio, which includes a main body 2701, a display portion 2702, and operation switches 2703 and 2704. The light emitting device of the present invention can be used for the display portion 2702. Moreover, although the vehicle-mounted car audio is shown in this embodiment, it may be used for a stationary car audio. Note that the display portion 2704 can suppress power consumption by displaying white characters on a black background. Note that in the case where a stick driver is provided in the light-emitting device used for the display portion 2704, it is preferable to divide the stick driver into several pieces.
[0207]
As described above, the application range of the present invention is extremely wide and can be used for electric appliances in various fields. Moreover, the electric appliance of a present Example can be obtained by using the light-emitting device which combined the structure of Examples 1-10 freely.
[0208]
【The invention's effect】
By implementing the present invention, the deposition position can be precisely controlled when depositing the EL material. Therefore, a light-emitting device having a high-definition pixel portion can be manufactured. In addition, since an EL material can be preferentially deposited on a necessary portion, the use efficiency of the EL material is increased, and the manufacturing cost can be reduced. Furthermore, by using the light emitting device of the present invention as a display portion, an electric appliance having a high-definition display portion can be obtained.
[Brief description of the drawings]
FIGS. 1A and 1B illustrate a top structure and a cross-sectional structure of a light-emitting device.
FIG. 2 is a diagram for explaining a film formation process of an EL material.
FIG. 3 is a diagram for explaining a process for forming an EL material by an evaporation method.
FIG. 4 is a diagram for explaining a film formation process of an EL material by an inkjet method.
FIG. 5 is a diagram for explaining a film formation process of an EL material by an ion plating method.
FIG 6 illustrates a cross-sectional structure of a pixel portion of a light-emitting device.
7A and 7B are a top view and a circuit structure of a pixel portion of a light emitting device.
FIG. 8 illustrates a method for manufacturing a light-emitting device.
FIG 9 illustrates a method for manufacturing a light-emitting device.
10A and 10B illustrate a method for manufacturing a light-emitting device.
FIG. 11 shows a structure of a switching TFT.
FIG. 12 is a diagram showing a structure of a current control TFT.
FIG. 13 illustrates an appearance of a light-emitting device.
FIG 14 illustrates a circuit configuration of a light-emitting device.
FIGS. 15A and 15B illustrate a top structure and a cross-sectional structure of a light-emitting device. FIGS.
FIG. 16 is a diagram for explaining a multi-chamfering process.
FIG. 17 is a diagram for explaining a multi-chamfering process.
FIG. 18 is a diagram for explaining a film formation process of an EL material.
FIG. 19 is a diagram for explaining a film formation process of an EL material.
FIG. 20 is a diagram showing an example of an electric appliance.
FIG. 21 is a diagram showing an example of an electric appliance.

Claims (7)

A TFT is formed above the insulator,
Forming a pixel electrode electrically connected to the TFT;
Forming a bank including a metal film so as to surround the pixel electrode;
The metal film is charged to a negative or positive polarity , a shadow mask disposed above the bank is charged to the same polarity as the metal film, and a luminescent material is charged, and the pixel has a polarity opposite to the metal film. A method for manufacturing a light-emitting device , wherein a layer containing a light-emitting material is formed in a portion surrounded by the bank while an electrode is charged . A TFT is formed above the insulator,
Forming a pixel electrode electrically connected to the TFT;
Forming a bank formed by laminating an insulating film and a metal film so as to surround the pixel electrode;
The metal film is charged to a negative or positive polarity , a shadow mask disposed above the bank is charged to the same polarity as the metal film, and a luminescent material is charged, and the pixel has a polarity opposite to the metal film. A method for manufacturing a light-emitting device , wherein a layer containing a light-emitting material is formed in a portion surrounded by the bank while an electrode is charged . A TFT is formed above the insulator,
Forming a pixel electrode electrically connected to the TFT;
Forming a bank including a metal film so as to surround the pixel electrode;
While charging the metal film to a negative or positive polarity, charging the vapor deposition chamber partition and the luminescent material to the same polarity as the metal film, and charging the pixel electrode to the opposite polarity to the metal film Forming a layer containing a luminescent material in the vapor deposition chamber in the vapor deposition chamber in a portion surrounded by the bank;
An electric field is formed inside a ring-shaped electrode disposed outside a hole provided in the vapor deposition boat provided with the luminescent material, and the inner side of the ring-shaped electrode is scattered when the luminescent material is scattered from the hole. A method for manufacturing a light-emitting device, wherein the light-emitting material is charged with the same polarity as that of the metal film by being passed through. A TFT is formed above the insulator,
Forming a pixel electrode electrically connected to the TFT;
Forming a bank formed by laminating an insulating film and a metal film so as to surround the pixel electrode;
While charging the metal film to a negative or positive polarity, charging the vapor deposition chamber partition and the luminescent material to the same polarity as the metal film, and charging the pixel electrode to the opposite polarity to the metal film Forming a layer containing a luminescent material in the vapor deposition chamber in the vapor deposition chamber in a portion surrounded by the bank;
An electric field is formed inside a ring-shaped electrode disposed outside a hole provided in the vapor deposition boat provided with the luminescent material, and the inner side of the ring-shaped electrode is scattered when the luminescent material is scattered from the hole. A method for manufacturing a light-emitting device, wherein the light-emitting material is charged with the same polarity as that of the metal film by being passed through. 3. The method for manufacturing a light-emitting device according to claim 1 , wherein the layer containing the light-emitting material is formed by an evaporation method, an ion plating method, or an ink-jet method. According to claim 2 or claim 4, when forming the banks, the line width of the metal film is a method for manufacturing a light emitting device, and forming to be narrower than the line width of the insulating film. In any one of claims 1 to 6, when forming the banks, a method for manufacturing a light emitting device, wherein the metal film is formed to have a tapered shape.

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