JP4101503B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

【０１２５】
(M.A.Baldo, D.F.O'Brien, Y.You, A.Shoustikov, S.Sibley, M.E.Thompson, S.R.Forrest, Nature 395 (1998) p.151.)
【０１２６】
上記の論文により報告された有機材料（Ｐｔ錯体）の分子式を以下に示す。
【０１２７】
【化２】

【０１２８】
(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.)
【０１２９】
上記の論文により報告された有機材料（Ｉｒ錯体）の分子式を以下に示す。
【０１３０】
【化３】

【０１３１】
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。
【０１３２】
なお、本実施例の有機材料は、実施例１〜実施例３に示した発光装置の有機化合物層において用いることが可能である。
【０１３３】
〔実施例５〕
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、本発明の発光装置を表示部に用いることにより様々な電気器具を完成させることができる。
【０１３４】
本発明により作製した発光装置を用いることにより完成した電気器具として、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好適である。それら電気器具の具体例を図１２に示す。
【０１３５】
図１２（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。本発明により作製した発光装置をその表示部２００３に用いたことにより完成させることができる。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。
【０１３６】
図１２（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。本発明により作製した発光装置をその表示部２１０２に用いたことにより完成させることができる。
【０１３７】
図１２（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。本発明により作製した発光装置をその表示部２２０３に用いたことにより完成させることができる。
【０１３８】
図１２（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２３０３、操作キー２３０４、赤外線ポート２３０５等を含む。本発明により作製した発光装置をその表示部２３０２に用いたことにより完成させることができる。
【０１３９】
図１２（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、本発明により作製した発光装置をこれら表示部Ａ、Ｂ２４０３、２４０４に用いたことにより完成させることができる。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。
【０１４０】
図１２（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。本発明により作製した発光装置は表示部２５０２に用いることができる。
【０１４１】
図１２（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。本発明により作製した発光装置をその表示部２６０２に用いたことにより完成させることができる。
【０１４２】
ここで図１２（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。本発明により作製した発光装置をその表示部２７０３に用いたことにより完成させることができる。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。
【０１４３】
なお、将来的に有機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。
【０１４４】
また、上記電気器具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。
【０１４５】
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。
【０１４６】
以上の様に、本発明を用いて作製された発光装置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できる。また、本実施例の電気器具は実施例１〜実施例３に示した発光装置をその表示部に用いて完成させることができる。
【０１４７】
【発明の効果】
以上説明したように、本発明により、配線形状を利用することによりこれまでマスクを用いて形成されていたバンクに替わる機能を持たせることが可能になった。また、その形状によりこれまで問題となっていた配線と対向電極とのショートの問題を解決することができた。以上により、本発明を用いることで発光装置の生産におけるプロセスを短縮することができるのでこれまでに比べてより高いスループットで生産することが可能となる。
【図面の簡単な説明】
【図１】 本発明による作製方法を示す図。
【図２】 本発明による作製方法を示す図。
【図３】 隔壁の作製を説明する図。
【図４】 隔壁を作製した際のＳＥＭ写真。
【図５】 画素の回路図。
【図６】 画素の回路図。
【図７】 作製工程を説明する図。
【図８】 作製工程を説明する図。
【図９】 作製工程を説明する図。
【図１０】 発光装置の封止構造を説明する図。
【図１１】 画素部を説明する上面図。
【図１２】 電気器具の一例を示す図。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an active matrix light-emitting device having a light-emitting element over a substrate, and the light-emitting device. Note that a light-emitting element refers to an element having a structure in which an anode, a cathode, and an organic compound layer containing a light-emitting organic material (hereinafter referred to as an organic material) from which EL (Electro Luminescence) is obtained are sandwiched therebetween. . Note that the light-emitting element here is also called an OLED (Organic Light Emitting Device). In this specification, a light-emitting panel in which a light-emitting element is sealed between a substrate and a cover material and a light-emitting module in which an IC is mounted on the light-emitting panel are collectively referred to as a light-emitting device. Furthermore, the present invention relates to an electric appliance using the light emitting device as a display unit.
[0002]
[Prior art]
Since the light emitting element emits light by itself, the visibility is high, a backlight necessary for a liquid crystal display (LCD) is not necessary, and it is optimal for thinning, and the viewing angle is not limited. Therefore, in recent years, a light emitting device using a light emitting element has attracted attention as an alternative to CRT and LCD.
[0003]
The light-emitting element includes a layer containing an organic material (hereinafter referred to as an organic compound layer) from which EL (Electro Luminescence: luminescence generated by applying an electric field) is obtained, an anode, and a cathode. Luminescence in an organic material includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state. In the light-emitting device of the present invention, a light-emitting element having either organic material can be used.
[0004]
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, the light-emitting element has a structure in which an anode / light-emitting layer / cathode is laminated in order, and in addition to this structure, an anode / hole injection layer / light-emitting layer / cathode and an anode / hole injection layer. In some cases, the light emitting layer / the electron transporting layer / the cathode are laminated in this order.
[0005]
In the case of forming a light-emitting element, there are film formation methods such as a vapor deposition method, a printing method, an inkjet method, and a spin coating method as a method for forming an organic compound layer for forming an organic compound layer.
[0006]
In particular, the vapor deposition method, which can be applied separately using a mask such as a metal mask, is one of the deposition methods widely used for the deposition of low molecular organic materials. In the case of forming an element, there is a problem that the pixel is destroyed when the metal mask is in contact with the pixel when forming the organic compound layer in order to form the light emitting element after the TFT is manufactured.
[0007]
However, in the light-emitting element manufacturing methods that have been performed so far, as disclosed in JP-A-11-339968, a passivation film is formed after the pixel electrode is formed, and the organic film is formed after removing the passivation film in the pixel electrode portion. A method of forming a compound layer and a counter electrode is employed. For this reason, a structure protected by a passivation film is formed so that the metal mask does not come into contact with the pixels. Note that the passivation film from which only the pixel electrode has been removed is referred to as a bank in this specification.
[0008]
As described above, by forming the bank before forming the organic compound layer and the counter electrode, the metal mask can be prevented from coming into contact with the pixel.
[0009]
[Problems to be solved by the invention]
In manufacturing a light emitting element, after a pixel electrode is formed for each pixel, a bank made of an insulating material is formed around the pixel.
[0010]
This bank not only protects the wiring and the like, but also forms the organic compound layer and the counter electrode by vapor deposition using a metal mask on the pixel electrode of the pixel. It contacts the compound layer and the counter electrode to protect them from destruction, and further has a role to prevent the electrode from short-circuiting with the wiring when the counter electrode is formed.
[0011]
However, when a bank is formed, there is a problem that one mask is added for the patterning.
[0012]
Therefore, an object of the present invention is to provide a method for manufacturing an active matrix light-emitting device that can have a function of changing to a bank without forming a bank, and a light-emitting device manufactured using the method.
[0013]
[Means for Solving the Problems]
The present invention has been made in order to solve the above-described problems, and has a structure in which the periphery of a pixel is protected by using an interlayer insulating film and a wiring formed on the interlayer insulating film in manufacturing an active matrix light-emitting device. By forming the metal mask, it is possible to prevent a metal mask used when a light emitting element is formed on the pixel from being in direct contact with the pixel.
[0014]
Furthermore, since the formation position of the organic compound layer and the counter electrode on the pixel electrode can be controlled by forming the above structure, a structure in which both electrodes forming the light emitting element are not short-circuited can be formed. .
[0015]
First, a TFT is formed on a substrate. Note that when the TFT gate electrode is manufactured, a first wiring for connecting the TFT and the pixel electrode is simultaneously formed in a part of a region where the light emitting element is formed. Note that in this specification, the first wiring referred to here is referred to as an electrode connection wiring. Then, an interlayer insulating film made of an insulating material is formed. Then, by partially etching the interlayer insulating film, the interlayer insulating film in the portion where the pixel is formed is also etched, and a part of the electrode connection wiring formed earlier appears on the surface.
[0016]
Next, a metal film and an insulating film are formed. First, the insulating film is patterned by a dry etching method. At this time, the metal film and the insulating film have a sufficiently large selection ratio. Next, the metal film is patterned using a wet etching method, and an isolation portion and a wiring (second wiring) are formed from the insulating film and the metal film, respectively. Note that, when the metal film is etched, the separation portion is also etched at the same time, but the material for forming the second wiring is selected so that the etching rate with respect to the etchant is higher than the material for forming the separation portion. Therefore, when viewed from the upper surface of the substrate on which the TFT is formed after the second wiring is formed, the area of the second wiring is smaller than that of the separation portion. Note that as an etching solution used for wet etching, a mixed solution including phosphoric acid, nitric acid, and acetic acid as well as hydrofluoric acid and a mixed solution containing the same can be used.
[0017]
Note that the second wiring is formed so as to be electrically connected to the source or drain of the TFT, and the second wiring is formed so as to overlap with part of the interlayer insulating film and the electrode connection wiring. Has been.
[0018]
As described above, the wiring and the isolation portion are formed on the interlayer insulating film. Note that in this specification, the second wiring and the separation portion formed over the interlayer insulating film are referred to as partition walls. Here, the case where different etching methods are used in the manufacture of the separation portion and the second wiring has been described. However, the same wet etching method may be used. Note that the current control TFT that controls the amount of current flowing through the light emitting element is in contact with and electrically connected to the electrode connection wiring.
[0019]
Note that after the partition wall is formed, the pixel electrode is formed so as to be in contact with the electrode connection wiring in a portion not overlapping with the second wiring for each pixel. Note that the pixel electrode formed here is formed without being in contact with the second wiring. Further, an organic compound layer is formed on the pixel electrode by vapor deposition using a metal mask.
[0020]
At this time, the metal mask may be provided so as not to come into contact with the substrate. Note that the organic compound layer can be formed at a desired position with high controllability by the metal mask and the partition.
[0021]
Next, a counter electrode is formed. Note that the electrode formed here is formed using the partition wall as a mask, so that it is not short-circuited with the pixel electrode or the wiring.
[0022]
As a result, the mask required for forming the bank is not necessary, and there are problems such as deterioration of the light emitting element due to moisture when the bank is formed of resin and the influence of temperature on the pixel electrode due to firing of the bank. In addition, a structure in which the periphery of the pixel is surrounded by an interlayer insulating film can be formed.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 1A illustrates one pixel formed in the pixel portion.
[0024]
First, an active layer is formed on the substrate 100 with Si. This forms the source region, drain region, and channel region of the TFT that will be fabricated later. Here, the regions surrounded by dotted lines in FIG. 1A are referred to as a region a (101a) and a region b (101b), respectively, and TFTs formed in the region a (101a) are used for switching later. The TFT formed in the region b (101b) is a current control TFT. That is, the active layer a (102a) forms a source region, a drain region, and a channel region of the switching TFT. The active layer b (102b) forms the source region, drain region, and channel region of the current control TFT.
[0025]
Reference numeral 103 denotes a gate signal line, and the wiring 104 connected to the gate signal line forms a gate electrode of a switching TFT to be formed later. Note that although a case of having a double gate structure is shown here, the gate structure is not limited to this, and may be a single gate or a multi-gate structure.
[0026]
Further, simultaneously with these wirings, a drain wiring a (105) having electrical connection with the drain of the switching TFT is formed. The drain wiring a (105) serves as the gate electrode of the current control TFT. In addition, a current supply line 106 that forms an electrical connection with the current control TFT is also formed. Note that the current supply line 106 supplies a current flowing through the light emitting element.
[0027]
Reference numeral 107 denotes an electrode connection wiring for electrically connecting the current control TFT and the pixel electrode.
[0028]
After these wirings are formed, an interlayer insulating film 108 is formed. Note that an insulating material is used as a material for forming the interlayer insulating film 108. Specifically, an inorganic resin film containing silicon such as silicon oxide or silicon nitride, or an organic resin film such as polyimide, polyamide, or acrylic may be used.
[0029]
Note that after the interlayer insulating film 108 is formed, a region for forming a pixel electrode is patterned to form a shape as shown in FIG. As shown here, the interlayer insulating film is formed so as to partially cover the electrode wiring 107.
[0030]
Here, FIG. 1C shows a cross-sectional view of a portion indicated by a dotted line AA ′ in FIG. That is, all the wiring is covered with the interlayer insulating film 108 in this portion.
[0031]
Next, in addition to the source signal line 109, the source wiring a (110) for electrically connecting the current control TFT and the current supply line 106, and the drain of the current control TFT and the electrode connection wiring 107 are electrically connected. A drain wiring b (111) is formed (FIG. 2A).
[0032]
Note that as a method for forming these wirings, after forming the structure shown in FIG. 1B, a metal material for forming the wirings is formed. The metal material used at this time may be formed using a metal material such as Al (aluminum) or Ti (titanium), an alloy film made of Al and Ti, or an alloy film of Al and Si.
[0033]
Further, a separation film is formed on the metal film using a material that can have a selective ratio with the etchant when etching is performed simultaneously with the metal film by a wet etching method. As described above, the material for forming the separation film may be a material that can take a selection ratio with the metal film during wet etching, and may be formed of an inorganic film such as silicon nitride or silicon oxide. You may form using metal films, such as Ti. Further, organic resins such as polyimide, polyamide, acrylic, and resist may be used.
[0034]
When the metal film and the separation film are formed, a wiring pattern is formed. At this time, after patterning the separation film, dry etching is performed to form a wiring pattern in which the metal film and the separation film are stacked. Further, when the wiring is wet etched, the metal film having a higher etching selectivity is etched. Therefore, when viewed from the top, the metal film is compared with the separation film as shown in FIG. It is getting smaller.
[0035]
Here, the portion indicated by the dotted line AA ′ in FIG. 2A, that is, the drain wiring b (111) is formed by patterning the metal film, and the separation portion 112 is formed by etching the separation film. A cross-sectional view at that time is shown in FIG. Note that in this specification, everything formed on the wiring by patterning the separation film is called a separation portion. Note that FIG. 2B shows a state in which the separation portion 112 is formed on the drain wiring b (111), but all the wirings formed by patterning the separation film in the present invention are all formed. The upper part is covered with a separation part.
[0036]
FIG. 2C is a cross-sectional view of a portion indicated by a dotted line BB ′ in FIG. As can be seen from the cross-sectional view of FIG. 2C, the electrode connection wiring 107 is formed to be in partial contact with the drain wiring b (111), so that it can be seen that it is electrically connected.
[0037]
Then, in a region C (113) shown in FIG. 2C, a pixel electrode for forming a light emitting element is patterned, and an organic compound layer and a counter electrode are formed thereon by vapor deposition using a metal mask. However, the partition formed by the drain wiring b (111) and the separation portion 112 can prevent contact between the pixel and the metal mask, and is opposed to the pixel electrode generated by the film formation position of the organic compound layer and the counter electrode. The problem of a short circuit with the electrode can be solved.
[0038]
Further, since the drain wiring b (111) is completely covered with the separation portion 112, the problem that both of them are short-circuited when the counter electrode forming the light emitting element is formed can be prevented.
[0039]
As described above, by implementing the present invention, the wiring can be used in place of the conventional bank, and the mask for forming the bank can be reduced, so that the manufacturing process can be shortened. Can do.
[0040]
Here, a method for manufacturing a shape including the wiring formed by the etching described above and a separation portion and a shape formed using the method will be described.
[0041]
In FIG. 3A, a metal film 201 is formed over a substrate 200, and a separation film 202 is formed over the metal film 201. A cross-sectional view taken along the dotted line AA ′ in FIG.
[0042]
Next, by performing dry etching patterning on the separation film 202 using the resist 203, a separation portion 204 having a desired pattern can be formed as shown in FIG.
[0043]
Note that the cross-sectional structure taken along the dotted line AA ′ in FIG. 3B at this time is as shown in FIG.
[0044]
Here, the metal film 201 is etched by a wet etching method. At this time, it is necessary to use a material having a sufficient selection ratio with respect to an etchant in etching for the material for forming the separation portion 204 and the material for forming the metal film 201.
[0045]
Here, when the metal film 201 is etched, a separation portion 204 and a wiring 205 as illustrated in FIG. 3C can be formed. Note that the cross-sectional structure taken along the dotted line AA ′ in FIG. 3C at this time is as shown in FIG.
[0046]
Here, FIG. 4A shows a SEM photograph taken of the cross-sectional structure of the separation portion 204 and the wiring 205 manufactured by the above method using Al for the metal film 201 and SiN for the separation portion 204.
[0047]
FIG. 4B shows details of the structure shown in the SEM photograph of FIG. In addition, the code | symbol used here respond | corresponds with the code | symbol used in FIG.
[0048]
In addition, as shown in FIG. 4B, the etching here is performed on the wiring film thickness (x), the etching distance (y) in the lateral direction of the upper part of the wiring with reference to the etching center (c), and the etching center ( The relationship with the lateral etching distance (α) at the lower part of the wiring with reference to c) is
[0049]
[Formula 1]
y = x + α (where α> 0)
[0050]
Isotropic etching. In this example, the wiring film thickness (x) = 500 nm, the lateral etching distance (α) = 400 nm in the lower part of the wiring, and the lateral etching distance (y) in the upper part of the wiring = 900 nm. It has become. In the present invention, the present invention is not limited to this, and may be adjusted as appropriate according to the wiring material, the wiring width, and the etching rate so that the above formula is established.
[0051]
【Example】
[Example 1]
In this embodiment, a structure of a pixel portion of a light-emitting device manufactured using the present invention will be described with an example.
[0052]
First, an enlarged view of the pixel portion 301 of the light emitting device is shown in FIG. Source signal lines (S 1 to Sx), current supply lines (V 1 to Vx), and gate signal lines (G 1 to Gy) are provided in the pixel portion 301.
[0053]
In this embodiment, the pixel 304 is a region provided with one source signal line (S1 to Sx), one current supply line (V1 to Vx), and one gate signal line (G1 to Gy). A plurality of pixels 304 are arranged in a matrix in the pixel portion 301.
[0054]
Next, an enlarged view of the pixel 304 is shown in FIG. In FIG. 6, reference numeral 305 denotes a switching TFT. The gate electrode of the switching TFT 305 is connected to the gate signal line G (G1 to Gx). One of the source region and the drain region of the switching TFT 305 is connected to the source signal line S (S1 to Sx), and the other is connected to the gate electrode of the current control TFT 306 and the capacitor 308 included in each pixel.
[0055]
The capacitor 308 is provided to hold the gate voltage (potential difference between the gate electrode and the source region) of the current control TFT 306 when the switching TFT 305 is in a non-selected state (off state). In the present embodiment, a configuration in which the capacitor 308 is provided is shown, but the present invention is not limited to this configuration, and a configuration in which the capacitor 308 is not provided may be employed.
[0056]
One of the source region and the drain region of the current control TFT 306 is connected to the current supply line V (V1 to Vx), and the other is connected to the light emitting element 307. The current supply line V is connected to the capacitor 308.
[0057]
The light emitting element 307 includes an anode, a cathode, and an organic compound layer provided between the anode and the cathode. When the anode is connected to the source region or drain region of the current control TFT 306, the anode serves as a pixel electrode and the cathode serves as a counter electrode. Conversely, when the cathode is connected to the source region or drain region of the current control TFT 306, the cathode serves as the pixel electrode and the anode serves as the counter electrode.
[0058]
A counter potential is applied to the counter electrode of the light emitting element 307. The power supply potential is applied to the current supply line V. The power source potential and the counter potential are given by a power source provided by an external IC or the like of the light emitting device of the present invention.
[0059]
As the switching TFT 305 and the current control TFT 306, either an n-channel TFT or a p-channel TFT can be used. However, when the source region or drain region of the current control TFT 306 is connected to the anode of the light emitting element 307, the current control TFT 306 is preferably a p-channel TFT. In addition, when the source region or the drain region of the current control TFT 306 is connected to the cathode of the light emitting element 307, the current control TFT 306 is preferably an n-channel TFT.
[0060]
Further, the switching TFT 305 and the current control TFT 306 may have a multi-gate structure such as a double gate structure or a triple gate structure instead of a single gate structure.
[0061]
Next, an example of a method for simultaneously manufacturing the above-described pixel portion and driver circuit TFTs (n-channel TFT and p-channel TFT) provided around the pixel portion on the same substrate will be described with reference to FIGS. I will explain.
[0062]
First, in this embodiment, a substrate 900 made of glass such as barium borosilicate glass represented by Corning # 7059 glass or # 1737 glass or aluminoborosilicate glass is used. Note that the substrate 900 is not limited as long as it is a light-transmitting substrate, and a quartz substrate may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used.
[0063]
Next, as illustrated in FIG. 7A, a base film 901 formed of an insulating film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is formed over a substrate 900. Although a two-layer structure is used as the base film 901 in this embodiment, a single-layer film of the insulating film or a structure in which two or more layers are stacked may be used. As the first layer of the base film 901, a plasma CVD method is used, and SiH _Four , NH _Three And N ₂ A silicon oxynitride film 901a formed using O as a reactive gas is formed to a thickness of 10 to 200 nm (preferably 50 to 100 nm). In this embodiment, a silicon oxynitride film 901a (composition ratio Si = 32%, O = 27%, N = 24%, H = 17%) having a thickness of 50 nm is formed. Next, as the second layer of the base film 901, a plasma CVD method is used, and SiH _Four And N ₂ A silicon oxynitride film 901b formed using O as a reactive gas is stacked to a thickness of 50 to 200 nm (preferably 100 to 150 nm). In this embodiment, a silicon oxynitride film 901b (composition ratio Si = 32%, O = 59%, N = 7%, H = 2%) having a thickness of 100 nm is formed.
[0064]
Next, semiconductor layers 902 to 905 are formed over the base film 901. The semiconductor layers 902 to 905 are formed by forming a semiconductor film having an amorphous structure by a known means (sputtering method, LPCVD method, plasma CVD method, or the like), and then known crystallization treatment (laser crystallization method, heat A crystalline semiconductor film obtained by performing a crystallization method or a thermal crystallization method using a catalyst such as nickel) is formed by patterning into a desired shape. The semiconductor layers 902 to 905 are formed with a thickness of 25 to 80 nm (preferably 30 to 60 nm). The material of the crystalline semiconductor film is not limited, but is preferably silicon (silicon) or silicon germanium (Si _X Ge _1-X (X = 0.0001 to 0.02)) It may be formed of an alloy or the like. In this example, a 55 nm amorphous silicon film was formed by plasma CVD, and then a solution containing nickel was held on the amorphous silicon film. This amorphous silicon film is dehydrogenated (500 ° C., 1 hour), then thermally crystallized (550 ° C., 4 hours), and further laser annealed to improve crystallization. Thus, a crystalline silicon film was formed. Then, semiconductor layers 902 to 905 were formed by patterning the crystalline silicon film using a photolithography method.
[0065]
Further, after the semiconductor layers 902 to 905 are formed, the semiconductor layers 902 to 905 may be doped with a small amount of impurity elements (boron or phosphorus) in order to control the threshold value of the TFT.
[0066]
When a crystalline semiconductor film is formed by laser crystallization, a pulse oscillation type or continuous emission type excimer laser, YAG laser, YVO _Four A laser can be used. When these lasers are used, it is preferable to use a method in which laser light emitted from a laser oscillator is linearly collected by an optical system and irradiated onto a semiconductor film. Crystallization conditions are appropriately selected by the practitioner, but when an excimer laser is used, the pulse oscillation frequency is 300 Hz and the laser energy density is 100 to 400 mJ / cm. ² (Typically 200-300mJ / cm ² ). When a YAG laser is used, the second harmonic is used and the pulse oscillation frequency is set to 30 to 300 kHz, and the laser energy density is set to 300 to 600 mJ / cm. ² (Typically 350-500mJ / cm ² ) Then, when the laser beam condensed linearly with a width of 100 to 1000 μm, for example, 400 μm is irradiated over the entire surface of the substrate, the superposition ratio (overlap ratio) of the linear laser light at this time is 50 to 90%. Good.
[0067]
Next, a gate insulating film 906 that covers the semiconductor layers 902 to 905 is formed. The gate insulating film 906 is formed of an insulating film containing silicon with a thickness of 40 to 150 nm by a plasma CVD method or a sputtering method. In this embodiment, a silicon oxynitride film (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 110 nm is formed by plasma CVD. Needless to say, the gate insulating film is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure.
[0068]
When a silicon oxide film is used, TEOS (Tetraethyl Orthosilicate) and O ₂ The reaction pressure is 40 Pa, the substrate temperature is 300 to 400 ° C., and the high frequency (13.56 MHz) power density is 0.5 to 0.8 W / cm. ² And can be formed by discharging. The silicon oxide film thus manufactured can obtain good characteristics as a gate insulating film by thermal annealing at 400 to 500 ° C. thereafter.
[0069]
Then, a heat-resistant conductive layer 907 for forming a gate electrode is formed over the gate insulating film 906 with a thickness of 200 to 400 nm (preferably 250 to 350 nm). The heat-resistant conductive layer 907 may be formed as a single layer, or may have a laminated structure including a plurality of layers such as two layers or three layers as necessary. The heat resistant conductive layer includes an element selected from Ta, Ti, and W, an alloy containing the element as a component, or an alloy film combining the elements. These heat-resistant conductive layers are formed by a sputtering method or a CVD method, and it is preferable to reduce the concentration of impurities contained in order to reduce the resistance. Particularly, the oxygen concentration is preferably 30 ppm or less. In this embodiment, the W film is formed with a thickness of 300 nm. The W film may be formed by sputtering using W as a target, or tungsten hexafluoride (WF ₆ Can also be formed by a thermal CVD method. In any case, in order to use as a gate electrode, it is necessary to reduce the resistance, and the resistivity of the W film is desirably 20 μΩcm or less. The resistivity of the W film can be reduced by increasing the crystal grains. However, when there are many impurity elements such as oxygen in W, crystallization is hindered and the resistance is increased. Therefore, in the case of sputtering, the resistivity is obtained by using a W target with a purity of 99.9999% and forming a W film with sufficient consideration so that impurities are not mixed in the gas phase during film formation. 9-20 μΩcm can be realized.
[0070]
On the other hand, when a Ta film is used for the heat-resistant conductive layer 907, it can be similarly formed by sputtering. The Ta film uses Ar as a sputtering gas. In addition, when an appropriate amount of Xe or Kr is added to the gas during sputtering, the internal stress of the film to be formed can be relaxed and the film can be prevented from peeling. The resistivity of the α-phase Ta film is about 20 μΩcm and can be used as a gate electrode, but the resistivity of the β-phase Ta film is about 180 μΩcm and is not suitable for a gate electrode. Since the TaN film has a crystal structure close to an α phase, an α phase Ta film can be easily obtained by forming a TaN film under the Ta film. Although not shown, it is effective to form a silicon film doped with phosphorus (P) with a thickness of about 2 to 20 nm under the heat-resistant conductive layer 907. This improves adhesion and prevents oxidation of the conductive film formed thereon, and at the same time, the alkali metal element contained in a trace amount in the heat-resistant conductive layer 907 diffuses into the gate insulating film 906 having the first shape. Can be prevented. In any case, the heat resistant conductive layer 907 preferably has a resistivity in the range of 10 to 50 μΩcm.
[0071]
Next, a resist mask 908 is formed using a photolithography technique. Then, a first etching process is performed. In this embodiment, an ICP etching apparatus is used, and the etching gas is Cl. ₂ And CF _Four 3.2 W / cm at a pressure of 1 Pa ² RF (13.56 MHz) power is applied to form plasma. 224 mW / cm also on the substrate side (sample stage) ² RF (13.56 MHz) power is applied, thereby applying a substantially negative self-bias voltage. Under this condition, the etching rate of the W film is about 100 nm / min. In the first etching process, the time during which the W film was just etched was estimated based on this etching rate, and the time when the etching time was increased by 20% was used as the etching time.
[0072]
Conductive layers 909 to 912 having a first tapered shape are formed by the first etching process. The angle of the tapered portion of the conductive layers 909 to 912 is formed to be 15 to 30 °. In order to perform etching without leaving a residue, overetching that increases the etching time at a rate of about 10 to 20% is performed. Since the selection ratio of the silicon oxynitride film (gate insulating film 906) to the W film is 2 to 4 (typically 3), the surface where the silicon oxynitride film is exposed is etched by about 20 to 50 nm by overetching. (FIG. 7B).
[0073]
Then, a first doping process is performed to add an impurity element of one conductivity type to the semiconductor layer. Here, a step of adding an impurity element imparting n-type is performed. The mask 908 having the first shape conductive layer is left as it is, and an impurity element imparting n-type is added by ion doping in a self-aligning manner using the first tapered conductive layers 909 to 912 as a mask. In order to add an impurity element imparting n-type through the tapered portion at the end portion of the gate electrode and the gate insulating film 906 so as to reach the semiconductor layer located thereunder, the dose amount is set to 1 × 10 ¹³ ~ 5x10 ¹⁴ atoms / cm ² The acceleration voltage is set to 80 to 160 keV. As an impurity element imparting n-type, an element belonging to Group 15, typically phosphorus (P) or arsenic (As), is used here, but phosphorus (P) is used. By such an ion doping method, the first impurity regions 914 to 917 have a concentration of 1 × 10 10. ²⁰ ~ 1x10 ^{twenty one} atomic / cm ^Three An impurity element imparting n-type is added in a concentration range of (FIG. 7C).
[0074]
In this step, depending on doping conditions, impurities may flow under the first shape conductive layers 909 to 912, and the first impurity regions 914 to 917 may overlap with the first shape conductive layers 909 to 912. Can also happen.
[0075]
Next, a second etching process is performed as shown in FIG. Similarly, the etching process is performed by an ICP etching apparatus, and CF is used as an etching gas. _Four And Cl ₂ RF power of 3.2 W / cm ² (13.56 MHz), bias power 45 mW / cm ² Etching is performed at 13.56 MHz and a pressure of 1.0 Pa. Conductive layers 918 to 921 having the second shape formed under these conditions are formed. A tapered portion is formed at the end, and a taper shape is formed in which the thickness gradually increases from the end toward the inside. Compared to the first etching process, the ratio of isotropic etching is increased by reducing the bias power applied to the substrate side, and the angle of the tapered portion is 30 to 60 °. The mask 908 is etched to scrape the end portion, thereby forming a mask 922. 7D, the surface of the gate insulating film 906 is etched by about 40 nm.
[0076]
Then, an impurity element imparting n-type conductivity is doped under a condition of a high acceleration voltage with a dose amount lower than that in the first doping treatment. For example, the acceleration voltage is 70 to 120 keV and 1 × 10 ¹³ / Cm ² First impurity regions 924 to 927 having an increased impurity concentration and second impurity regions 928 to 931 in contact with the first impurity regions 924 to 927 are formed. In this step, depending on the doping conditions, impurities may flow under the second shape conductive layers 918 to 921, and the second impurity regions 928 to 931 may overlap with the second shape conductive layers 918 to 921. Can also happen. The impurity concentration in the second impurity region is 1 × 10 ¹⁶ ~ 1x10 ¹⁸ atoms / cm ^Three (FIG. 8A).
[0077]
Then, as shown in FIG. 8B, impurity regions 933 (933a, 933b) and 934 (934a, 934a, 934a, 934b, 903a, 933b, 934a, 934a, 933a, 933b, 934a, and 934b) 934b). Also in this case, an impurity element imparting p-type is added using the second shape conductive layers 918 and 921 as a mask, and an impurity region is formed in a self-aligning manner. At this time, the semiconductor layers 903 and 904 forming the n-channel TFT are covered with a resist mask 932 so as to cover the entire surface. The impurity regions 933 and 934 formed here are diborane (B ₂ H ₆ ) Using an ion doping method. The concentration of the impurity element imparting p-type in the impurity regions 933 and 934 is 2 × 10 ²⁰ ~ 2x10 ^{twenty one} atoms / cm ^Three To be.
[0078]
However, the impurity regions 933 and 934 can be divided into two regions containing an impurity element imparting n-type in detail. The third impurity regions 933a and 934a are 1 × 10 ²⁰ ~ 1x10 ^{twenty one} atoms / cm ^Three The fourth impurity regions 933b and 934b include an impurity element imparting n-type at a concentration of 1 × 10 ¹⁷ ~ 1x10 ²⁰ atoms / cm ^Three An impurity element imparting n-type is contained at a concentration of. However, the concentration of the impurity element imparting p-type in these impurity regions 933b and 934b is 1 × 10. ¹⁹ atoms / cm ^Three As described above, in the third impurity regions 933a and 934a, the concentration of the impurity element imparting p-type is 1.5 to 3 times the concentration of the impurity element imparting n-type. Since the third impurity region functions as the source region and the drain region of the p-channel TFT, no problem occurs.
[0079]
After that, as illustrated in FIG. 8C, a first interlayer insulating film 937 is formed over the conductive layers 918 to 921 and the gate insulating film 906 having the second shape. The first interlayer insulating film 937 may be formed using a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a stacked film in which these are combined. In any case, the first interlayer insulating film 937 is formed from an inorganic insulating material. The thickness of the first interlayer insulating film 937 is 100 to 200 nm. When a silicon oxide film is used as the first interlayer insulating film 937, TEOS and O ₂ The reaction pressure is 40 Pa, the substrate temperature is 300 to 400 ° C., and the high frequency (13.56 MHz) power density is 0.5 to 0.8 W / cm. ² And can be formed by discharging. In the case where a silicon oxynitride film is used as the first interlayer insulating film 937, SiH is formed by plasma CVD. _Four , N ₂ O, NH _Three Silicon oxynitride film manufactured from SiH or SiH _Four , N ₂ A silicon oxynitride film formed from O may be used. The production conditions in this case are a reaction pressure of 20 to 200 Pa, a substrate temperature of 300 to 400 ° C., and a high frequency (60 MHz) power density of 0.1 to 1.0 W / cm. ² Can be formed. Further, as the first interlayer insulating film 937, SiH _Four , N ₂ O, H ₂ Alternatively, a silicon oxynitride silicon film manufactured from the above may be used. Similarly, the silicon nitride film is made of SiH by plasma CVD. _Four , NH _Three It is possible to make from.
[0080]
Then, a step of activating the impurity element imparting n-type or p-type added at each concentration is performed. This step is performed by a thermal annealing method using a furnace annealing furnace. In addition, a laser annealing method or a rapid thermal annealing method (RTA method) can be applied. In the thermal annealing method, the oxygen concentration is 1 ppm or less, preferably 0.1 ppm or less in a nitrogen atmosphere at 400 to 700 ° C., typically 500 to 600 ° C. In this example, the temperature is 550 ° C. for 4 hours. Heat treatment was performed. In the case where a plastic substrate having a low heat resistant temperature is used as the substrate 501, it is preferable to apply a laser annealing method.
[0081]
Following the activation step, the step of hydrogenating the semiconductor layer is performed by changing the atmosphere gas and 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 performed in the semiconductor layer by thermally excited hydrogen. ¹⁶ -10 ¹⁸ /cm ^Three This is a step of terminating the dangling bond. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed. In any case, the defect density in the semiconductor layers 902 to 905 is 10 ¹⁶ /cm ^Three It is desirable to set it as follows, and for that purpose, hydrogen may be added at about 0.01 to 0.1 atomic%.
[0082]
Then, a second interlayer insulating film 939 made of an organic insulating material is formed with an average film thickness of 1.0 to 2.0 μm. As the organic resin material, polyimide, acrylic, polyamide, polyimide amide, BCB (benzocyclobutene), photosensitive acrylic, or the like can be used. For example, when using a type of polyimide that is thermally polymerized after being applied to the substrate, it is formed by baking at 300 ° C. in a clean oven. When acrylic is used, a two-component one is used, and after mixing the main material and the curing agent, applying to the entire surface of the substrate using a spinner, preheating at 80 ° C. for 60 seconds with a hot plate. It can be formed by baking at 250 ° C. for 60 minutes in a clean oven.
[0083]
Thus, the surface can be satisfactorily planarized by forming the second interlayer insulating film 939 from an organic insulating material. Moreover, since the organic resin material generally has a low dielectric constant, parasitic capacitance can be reduced. However, since it is hygroscopic and not suitable as a protective film, it is preferably used in combination with a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or the like formed as the first interlayer insulating film 937 as in this embodiment. .
[0084]
Thereafter, a resist mask having a predetermined pattern is formed, and contact holes are formed in the respective semiconductor layers to reach impurity regions serving as source regions or drain regions. The contact hole is formed by a dry etching method. In this case, CF is used as an etching gas. _Four , O ₂ The second interlayer insulating film 939 made of an organic resin material is first etched using a mixed gas of He and He, and then the etching gas is changed to CF. _Four , O ₂ The first interlayer insulating film 937 is etched as follows. Further, in order to increase the selectivity with the semiconductor layer, the etching gas is changed to CHF. _Three The contact hole can be formed by etching the gate insulating film 906 while switching to.
[0085]
A wiring layer 940 made of a conductive metal film is formed by a sputtering method or a vacuum evaporation method. Further, on the wiring layer 940, a separation layer 941 is formed which is made of a material that increases the selectivity with respect to the wiring layer and the etchant during etching. Note that the separation layer 941 may be formed of an inorganic material such as a nitride film or an oxide film, or may be formed of an organic resin such as polyimide, polyamide, or BCB (benzocyclobutene). Further, it may be formed of a metal material.
[0086]
Here, the separation layer 941 is patterned with a mask and then etched to form source wirings 942a to 945a, drain wirings 946a to 948a, and separation portions 942b to 948b. Note that in this specification, a structure formed of the separation layer and the wiring is referred to as a partition wall. Although not shown, in this embodiment, this wiring is formed of a laminated film of a Ti film having a thickness of 50 nm and an alloy film (alloy film of Al and Ti) having a thickness of 500 nm.
[0087]
Next, a transparent conductive film is formed thereon with a thickness of 80 to 120 nm and patterned to form a pixel electrode 949 (FIG. 9B). In this embodiment, since the pixel electrode 949 is an electrode that functions as an anode, an indium tin oxide (ITO) film or indium oxide is mixed with 2 to 20% zinc oxide (ZnO). A pixel electrode 949 is formed by using a film.
[0088]
Further, the pixel electrode 949 is formed in contact with and overlapping with the contact wiring 923 that is electrically connected to the drain wiring 946a, so that electrical connection with the drain region of the current control TFT 963 is formed.
[0089]
Next, as shown in FIG. 9B, an organic compound layer 950, a cathode 951 which is a counter electrode, and a passivation film 952 are formed by an evaporation method. At this time, before forming the organic compound layer 950, it is desirable to perform heat treatment on the pixel electrode 947 to completely remove moisture. In this embodiment, an electrode formed of an Mg: Ag alloy is used as the cathode of the light emitting element, but other known materials may be used.
[0090]
Note that the organic compound layer 950 is formed by stacking a plurality of layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a buffer layer in addition to the light-emitting layer. The structure of the organic compound layer 950 used in this example will be described in detail below.
[0091]
In this example, copper phthalocyanine is used as the hole injection layer, and MTDATA is used as the hole transport layer.
(4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine) was formed by vapor deposition. However, PEDOT, which is a polythiophene derivative, can be used as the hole injection layer, and α-NPD, polyphenylene vinylene (PPV), or the like can be used as the hole transport layer.
[0092]
Next, a light emitting layer is formed. In this embodiment, an organic compound layer showing different light emission is formed by using different materials for the light emitting layer. In this embodiment, an organic compound layer that emits red, green, and blue light is formed.
[0093]
The light emitting layer that develops red color is Alq. _Three It is formed using a material doped with DCM. Other Eu complexes (Eu (DCM) _Three (Phen), aluminum quinolinato complex (Alq _Three ) Using DCM-1 as a dopant can be used, but other known materials can also be used.
[0094]
In addition, the light emitting layer that develops a green color is composed of CBP and Ir (ppy). _Three Can be formed by co-evaporation. In addition to this, an aluminum quinolinato complex (Alq _Three ), A benzoquinolinolatoberyllium complex (BeBq) can be used. Furthermore, an aluminum quinolinato complex (Alq _Three ) Using a material such as coumarin 6 or quinacridone as a dopant is also possible, but other known materials can also be used.
[0095]
Further, the light emitting layer that develops a blue color can be a distyryl derivative DPVBi, a zinc complex having an azomethine compound as a ligand, or DPVBi doped with perylene, but other known materials can be used. Also good.
[0096]
Further, after the light emitting layer is formed, an electron transport layer or an electron injection layer may be formed. In this embodiment, a material such as a 1,3,4-oxadiazole derivative or a 1,2,4-triazole derivative (TAZ) is used for the electron transport layer. Furthermore, lithium fluoride (LiF), aluminum oxide (Al ₂ O _Three ), A material such as lithium acetylacetonate (Liacac) may be used to form the buffer layer 206.
[0097]
Note that the thickness of the organic compound layer 950 having such a stacked structure is 10 to 400 [nm] (typically 60 to 150 [nm]), and the thickness of the cathode 951 is 80 to 200 [nm] (typical). 100 to 150 [nm]).
[0098]
After the organic compound layer 950 is formed, a cathode 951 is formed by an evaporation method, and the light-emitting element 954 is completed. In this embodiment, an Mg: Ag alloy is used as the conductive film that becomes the cathode 951 of the light-emitting element 954. However, an Al—Li alloy film (an alloy film of aluminum and lithium) It is also possible to use a film formed by co-evaporation of the element to which it belongs and aluminum. Note that co-evaporation refers to a vapor deposition method in which a vapor deposition cell is simultaneously heated and different substances are mixed in a film formation stage.
[0099]
Note that after the formation of the cathode 951, a passivation film 952 is formed. Note that by providing the passivation film 952, the organic compound layer 950 and the cathode 951 can be protected from moisture and oxygen. In this embodiment, a silicon nitride film having a thickness of 300 nm is provided as the passivation film 952. The passivation film 952 may be continuously formed after the cathode 951 is formed without being released to the atmosphere.
[0100]
Thus, a light emitting device having a structure as shown in FIG. 9C is completed. Note that a portion where the pixel electrode 949, the organic compound layer 950, and the cathode 951 overlap corresponds to the light-emitting element 954.
[0101]
A p-channel TFT 960 and an n-channel TFT 961 are TFTs included in the driver circuit and form a CMOS. The switching TFT 962 and the current control TFT 963 are TFTs included in the pixel portion, and the driver circuit TFT and the pixel portion TFT can be formed over the same substrate.
[0102]
Note that in the case of a light-emitting device using a light-emitting element, the power supply voltage of the drive circuit is about 5 to 6 V, and the maximum is about 10 V. Further, since it is necessary to operate the driving circuit at high speed, it is preferable that the gate capacitance of the TFT is small. Therefore, as in this embodiment, in the driving circuit of the light emitting device using the light emitting element, the second impurity region 929 and the fourth impurity region 933b included in the semiconductor layer of the TFT are gate electrodes 918 and 919, respectively. It is preferable to have a configuration that does not overlap.
[0103]
Thus, a light-emitting panel in which a light-emitting element is formed over a substrate can be formed as illustrated in FIG.
[0104]
Note that after the light-emitting panel is formed, the light-emitting device of the present invention can be completed by sealing the light-emitting panel and electrically connecting to an external power source by an FPC.
[0105]
[Example 2]
In this example, a method for completing the light-emitting panel manufactured in Example 1 up to FIG. 9C as a light-emitting device will be described in detail with reference to FIGS.
[0106]
10A is a top view illustrating a state where the light-emitting element is sealed, and FIG. 10B is a cross-sectional view taken along line AA ′ in FIG. 10A. Reference numeral 1001 indicated by a dotted line denotes a source side driver circuit, 1002 denotes a pixel portion, and 1003 denotes a gate side driver circuit. Further, reference numeral 1004 denotes a cover material, and 1005 denotes a sealing agent. A space 1007 is provided on the inner side surrounded by the sealing agent 1005.
[0107]
Reference numeral 1008 denotes a wiring for transmitting signals input to the source side driver circuit 1001 and the gate side driver circuit 1003, and receives a video signal and a clock signal from an FPC (flexible printed circuit) 1009 serving as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. The light-emitting device in this specification includes not only a light-emitting module in which an FPC or a PWB is attached to a light-emitting panel but also a light-emitting module on which an IC is mounted.
[0108]
Next, a cross-sectional structure is described with reference to FIG. A pixel portion 1002 and a gate side driver circuit 1003 are formed above the substrate 1000, and the pixel portion 1002 is formed by a plurality of pixels including a current control TFT 1011 and a transparent electrode 1012 electrically connected to the drain thereof. The The gate side driver circuit 1003 is formed using a CMOS circuit (see FIG. 9) in which an n-channel TFT 1013 and a p-channel TFT 1014 are combined.
[0109]
The pixel electrode 1012 functions as an anode of the light emitting element. In addition, an interlayer insulating film 1006 is formed on both ends of the pixel electrode 1012, and an organic compound layer 1016 and a cathode 1017 which is a counter electrode of the light emitting element are formed on the pixel electrode 1012.
[0110]
The cathode 1017 also functions as a wiring common to a plurality of pixels, and is electrically connected to the FPC 1010 through a connection wiring 1009. Further, all elements included in the pixel portion 1002 and the gate side driver circuit 1003 are covered with a passivation film 1018.
[0111]
In addition, a cover material 1004 is bonded with a sealant 1005. Note that a spacer made of a resin film may be provided in order to ensure a space between the cover material 1004 and the light emitting element. The inside of the sealant 1005 is a sealed space, and is filled with an inert gas such as nitrogen or argon. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space.
[0112]
As the cover material 1004, glass, ceramics, plastic, or metal can be used. However, when light is emitted to the cover material 1004 side, the cover material 1004 must be translucent. As the plastic, FRP (Fiberglass-Reinforced Plastics), PVF (polyvinyl fluoride), Mylar, polyester or acrylic can be used.
[0113]
By sealing the light emitting panel with the cover material 1004 and the sealant 1005 as described above, the light emitting element can be completely shut off from the outside, and deterioration due to oxidation of an organic compound layer such as moisture or oxygen from the outside. Can prevent the entry of substances that promote Therefore, a highly reliable light-emitting device can be obtained.
[0114]
Note that this embodiment can be freely combined with Embodiment 1.
[0115]
Example 3
Here, a top view of a pixel portion of a light-emitting element manufactured by the method shown in Embodiment 1 is shown in FIG. Note that the circuit configuration on the substrate is as shown in FIG. 11A, in which a source side driver circuit 1101, a gate side driver circuit 1102, and a pixel portion 1103 are provided.
[0116]
FIG. 11B shows an enlarged view of a pixel electrode 110 (referred to as an anode in this embodiment) of the light-emitting element and a region a (1104) of the pixel portion 1103 where the organic compound layer is formed.
[0117]
The source signal line 1105 is electrically connected to the source side driver circuit 1101. Note that a current supply line 1106 for supplying a current flowing through the light emitting element is also formed in parallel with the source signal line 1105.
[0118]
A plurality of pixels 1107 formed in a matrix in the pixel portion 1103 are each surrounded by an interlayer insulating film 1108.
[0119]
After the organic compound layer is formed, a cathode 1109 which is a counter electrode is formed as shown in FIG. 11C. The source signal line 1105 and the current supply line 1106 formed over the interlayer insulating film 1108 are connected to the pixel 1107. Compared with the substrate surface, the cathode 1109 is disconnected because it is higher than the substrate surface. That is, the cathode 1109 is common to the same pixel columns arranged in the vertical direction toward the paper surface, but the pixel columns arranged in the horizontal direction are not common.
[0120]
Therefore, a connection wiring 1110 is formed as shown in FIG. Since the connection wiring 1110 is formed at the same time as the electrode wiring and the gate electrode, the cathode 1109 serving as a wiring common to a plurality of pixels on the interlayer insulating film 1108 is connected to the connection wiring 1110 in FIG. All the pixels are connected to an external power source by being electrically connected at the connection portion shown. Note that the connection wiring 1110 may be provided at a lower portion of the pixel portion or an upper portion thereof as shown in FIG. Furthermore, a structure provided above and below may be used. By forming these structures, a linear defect caused by cutting of the cathode 1109 shared by the pixel columns can be prevented. Note that this embodiment can be freely combined with the structure shown in Embodiment 1 or Embodiment 2.
[0121]
Example 4
In the light-emitting device using the present invention, an organic material (also referred to as a triplet compound) that can use phosphorescence from triplet excitons for light emission can be used. A light-emitting device using an organic material 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 light emitting element.
[0122]
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.)
[0123]
The molecular formula of the organic material (coumarin dye) reported by the above paper is shown below.
[0124]
[Chemical 1]

[0125]
(MABaldo, DFO'Brien, Y.You, A.Shoustikov, S.Sibley, METhompson, SRForrest, Nature 395 (1998) p.151.)
[0126]
The molecular formula of the organic material (Pt complex) reported by the above paper is shown below.
[0127]
[Chemical 2]

[0128]
(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.)
[0129]
The molecular formula of the organic material (Ir complex) reported by the above paper is shown below.
[0130]
[Chemical 3]

[0131]
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.
[0132]
Note that the organic material of this embodiment can be used in the organic compound layer of the light-emitting device shown in Embodiments 1 to 3.
[0133]
Example 5
Since a light-emitting device using a light-emitting element is a self-luminous type, it is superior in visibility in a bright place and has a wide viewing angle as compared with a liquid crystal display device. Therefore, various electric appliances can be completed by using the light emitting device of the present invention for the display portion.
[0134]
As electric appliances completed by using the light emitting device manufactured according to the present invention, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, a sound reproducing device (car audio, audio component, etc.), a notebook type personal computer 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 the screen from an oblique direction is suitable because the width of the viewing angle is important. Specific examples of these electric appliances are shown in FIG.
[0135]
FIG. 12A 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. It can be completed by using the light emitting device manufactured according to the present invention for the display portion 2003. Since a light-emitting device having a 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.
[0136]
FIG. 12B illustrates 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. It can be completed by using the light emitting device manufactured according to the present invention for the display portion 2102.
[0137]
FIG. 12C 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. It can be completed by using the light emitting device manufactured according to the present invention for the display portion 2203.
[0138]
FIG. 12D illustrates a mobile computer, which includes a main body 2301, a display portion 2302, a switch 2303, operation keys 2304, an infrared port 2305, and the like. It can be completed by using the light emitting device manufactured according to the present invention for the display portion 2302.
[0139]
FIG. 12E 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 A 2403, a display portion B 2404, 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, the light-emitting device manufactured according to the present invention can be completed by using the 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.
[0140]
FIG. 12F 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 manufactured according to the present invention can be used for the display portion 2502.
[0141]
FIG. 12G 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. . It can be completed by using the light emitting device manufactured according to the present invention for the display portion 2602.
[0142]
Here, FIG. 12H 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. It can be completed by using the light emitting device manufactured according to the present invention 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.
[0143]
If the emission luminance of the organic 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.
[0144]
In addition, the electric appliances often display information distributed through electronic communication lines such as the Internet or CATV (cable television), and in particular, opportunities to display moving image information are increasing. Since the response speed of the organic material is very high, the light-emitting device is preferable for displaying moving images.
[0145]
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.
[0146]
As described above, the applicable range of the light-emitting device manufactured using the present invention is so wide that the light-emitting device can be used for electric appliances in various fields. In addition, the electric appliance of this embodiment can be completed by using the light emitting device shown in Embodiments 1 to 3 for the display portion.
[0147]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a function that replaces a bank that has been formed using a mask by using a wiring shape. In addition, the short circuit between the wiring and the counter electrode, which has been a problem due to its shape, can be solved. As described above, by using the present invention, a process for producing a light emitting device can be shortened, so that it is possible to produce with higher throughput than before.
[Brief description of the drawings]
FIG. 1 is a view showing a manufacturing method according to the present invention.
FIG. 2 is a view showing a manufacturing method according to the present invention.
FIGS. 3A and 3B illustrate a method for manufacturing a partition wall. FIGS.
FIG. 4 is an SEM photograph when a partition wall is produced.
FIG. 5 is a circuit diagram of a pixel.
FIG. 6 is a circuit diagram of a pixel.
FIGS. 7A to 7C illustrate a manufacturing process. FIGS.
FIG. 8 illustrates a manufacturing process.
FIG. 9 illustrates a manufacturing process.
FIG 10 illustrates a sealing structure of a light-emitting device.
FIG. 11 is a top view illustrating a pixel portion.
FIG. 12 is a diagram showing an example of an electric appliance.

Claims (7)

On a substrate, a light-emitting device having a source, a TFT having a drain and a channel region, and a light emitting element,
The light-emitting element includes a first electrode, an organic compound layer, and a second electrode,
A first wiring electrically connected to the first electrode on the substrate;
An insulating film formed on the first wiring;
A second wiring formed on the first wiring and the insulating film and electrically connected to the source or the drain ;
A separation portion formed on the second wiring,
Wherein the separation unit is Rukoto formed at a lower material etching rate as compared to the material forming the second wiring, the light emitting device, characterized in that a large area when viewed from the top surface than said second wiring. On a substrate, a light-emitting device having a source, a TFT having a drain and a channel region, and a light emitting element,
The light-emitting element includes a first electrode, an organic compound layer, and a second electrode,
A first wiring electrically connected to the first electrode on the substrate;
An insulating film formed on the first wiring;
A second wiring formed on the first wiring and the insulating film and electrically connected to the source or the drain ;
A separation portion formed on the second wiring,
The isolation portion is formed of a material having a slower etching rate than the material forming the second wiring, so that the area viewed from the upper surface is larger than the second wiring,
The light-emitting device, wherein the separation portion serves as a mask in forming the organic compound layer and the second electrode. In claim 1 or claim 2 ,
The light emitting device is used as a display unit, and is selected from a display device, a digital still camera, a notebook personal computer, a mobile computer, a portable image reproducing device equipped with a recording medium, a goggle type display, a video camera, and a mobile phone. A light emitting device characterized by completing one kind. A method for manufacturing a light-emitting device having a TFT and a light-emitting element over a substrate,
Forming source, drain and channel regions of the TFT on the substrate;
Forming a gate insulating film covering the source, the drain and the channel region;
Forming a gate electrode and a first wiring of the TFT;
Forming an insulating film on the gate electrode and the first wiring;
Removing a portion of the insulating film formed on the first wiring;
Forming a second wiring electrically connected to the source or the drain over the first wiring and the insulating film;
A method for manufacturing a light-emitting device, wherein a separation portion is formed using a material whose etching rate is lower than that of a material for forming the second wiring on the second wiring. A method for manufacturing a light-emitting device having a TFT and a light-emitting element over a substrate,
Forming source, drain and channel regions of the TFT on the substrate;
Forming a gate insulating film covering the source, the drain and the channel region;
Forming a gate electrode and a first wiring of the TFT;
Forming an insulating film on the gate electrode and the first wiring;
Removing a part of the insulating film formed on the first wiring;
Forming a second wiring electrically connected to the source or the drain on the first wiring and the insulating film;
Before SL to form the separating portion at a slower etching rate material than the material forming said second wiring on the second wiring,
The method for manufacturing a light emitting device and forming the organic compound layer and the second electrode of the light emitting element the separation unit as a mask. A method for manufacturing a light-emitting device having a TFT and a light-emitting element over a substrate,
Forming source, drain and channel regions of the TFT on the substrate;
Forming a gate insulating film covering the source, the drain and the channel region;
Forming a gate electrode and a first wiring of the TFT;
Forming a first insulating film on the gate electrode and the first wiring;
Removing a part of the first insulating film formed on the first wiring;
Forming a second wiring electrically connected to the source or the drain over the first wiring and the first insulating film;
Before Symbol the second insulating film at a slower etching rate material is formed as compared with the material forming said second wiring on the second wiring,
A method for manufacturing a light-emitting device, wherein the second wiring and the second insulating film are etched by a wet etching method to form a separation portion having the second insulating film . A method for manufacturing a light-emitting device having a TFT and a light-emitting element over a substrate,
Forming source, drain and channel regions of the TFT on the substrate;
Forming a gate insulating film covering the source, the drain and the channel region;
Forming a gate electrode and a first wiring of the TFT;
Forming an insulating film on the gate electrode and the first wiring;
Removing a part of the insulating film formed on the first wiring;
Forming a second wiring electrically connected to the source or the drain on the first wiring and the insulating film;
Forming a separation portion on the second wiring with a material having a slower etching rate than the material forming the second wiring ;
Forming a first electrode of the light emitting element in contact with the first wiring;
Manufacturing method of the that the separation unit as a mask formed form the organic compound layer and the second electrode of the light emitting element emitting device.

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