JP2004289044A - Thin film transistor element sheet and its producing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a high precision thin film transistor simply and efficiently without requiring a vacuum system or photolithography. <P>SOLUTION: The process for producing a thin film transistor element sheet where a plurality of thin film transistor elements are coupled on a support through a gate bus line and a source bus line comprises a step for forming a fluid electrode material repellent region on a channel region or the support directly or through a second layer, and a step for forming at least a source electrode and a drain electrode by feeding the fluid electrode material onto the channel region or the support directly or through the second layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０１５１】
発振波長８３０ｎｍ、出力１００ｍＷの半導体レーザで２００ｍＪ／ｃｍ^２のエネルギー密度でゲートバスラインおよびゲート電極のパターンを露光した後、アルカリ水溶液で現像し、レジスト像を得た。
【０１５２】
さらにその上に、スパッタ法により、厚さ３００ｎｍのアルミニウム皮膜を一面に成膜した後、ＭＥＫで上記光感応性樹脂層の残存部を除去することで、ゲートバスライン１１およびゲート電極を作製した。
【０１５３】
（陽極酸化皮膜形成工程）
以上のフィルム基板をよく洗浄した後、５０ｇ／Ｌのホウ酸アンモニウム水溶液中で、５分間、１００Ｖの定電圧電源から供給される直流を用いて陽極酸化皮膜（図示していない）を作製し、超純水でよく洗浄した。
【０１５４】
（ゲート絶縁層形成工程）
さらにフィルム温度２００℃にて、上述した大気圧プラズマ法の使用ガスを下記に変更し、厚さ３０ｎｍの酸化ケイ素層であるゲート絶縁層（図示していない）を設けた。
【０１５５】
（使用ガス）
不活性ガス：ヘリウム９８．２５体積％
反応性ガス：酸素ガス１．５体積％
反応性ガス：テトラエトキシシラン蒸気（ヘリウムガスにてバブリング）０．２５体積％
（有機半導体層形成工程）
次に、ゲート絶縁層（図示していない）の上に、下記化合物Ｃのクロロホルム溶液を、ピエゾ方式のインクジェット法を用いて、チャネルを形成すべき領域に吐出し、窒素ガス中で、５０℃で３分乾燥し、２００℃で１０分の熱処理を行ったところ、厚さ５０ｎｍのペンタセン薄膜である有機半導体層３を形成した。
【０１５６】
【化２】

【０１５７】
工程（２）：流動性電極材料反発領域６、Ａ、Ｂの形成
有機半導体層３上にスクリーン印刷法により、シリコーン接着剤（東レダウコーニングシリコーン（株）製、ＳＥ９１８５）を付着させ、５０℃にて硬化させ、幅２０μｍ、厚さ３μｍのシリコーンゴムから成る流動性電極材料反発領域層６、Ａ、Ｂを各々形成した。
【０１５８】
工程（３）：ソース電極、ドレイン電極、画素電極、ソースバスラインの形成電極形成材料である、０．０１質量％のノニオン界面活性剤（例えば、ニッコーケミカルズ製ＮＰ１５など）を添加したポリスチレンスルホン酸とポリ（エチレンジオキシチオフェン）の水分散液（バイエル製 Ｂａｙｔｒｏｎ Ｐ）を塗布し、流動性電極材料反発領域６、Ａ、Ｂにより塗布膜が分断されたところで、６０℃で乾燥させ、膜厚０．２μｍの前記電極形成材料の塗膜が形成された。さらに銀ペーストを塗布し、同様に流動性電極材料反発領域６、Ａ，Ｂにより塗布膜が分断されたところで、６０℃で乾燥させ、２００℃で熱処理することにより、膜厚２μｍの銀ペーストの塗膜が形成された。
【０１５９】
以上の工程により、本発明のＴＦＴシートが製造され、良好に駆動することができる。
【０１６０】
実施例２
《薄膜トランジスタ素子シート２の作製》
実施例１の薄膜トランジスタ１の作製において、下記のような変更を加えた以外は同様にして、薄膜トランジスタ素子シート２を作製した。
【０１６１】
（有機半導体層３の形成を下記のように変更）
ＺｎおよびＮｉの含有量が１０ｐｐｍ以下になるよう良く精製した、ポリ（３−ヘキシルチオフェン）のｒｅｇｉｏｒｅｇｕｌａｒ体（アルドリッチ社製）のクロロホルム溶液を調製した。この溶液を、ピエゾ型のインクジェットを用いて吐出しパターニングし、室温で乾燥させた後、Ｎ_２ガス置換雰囲気中で、５０℃、３０分間の熱処理を施した。このとき、ポリ（３−ヘキシルチオフェン）の膜厚は３０ｎｍであった。
【０１６２】
以上の工程により、本発明のＴＦＴシートが製造され、良好に駆動することができる。
【０１６３】
実施例３
《薄膜トランジスタ素子シート３の作製》
実施例１にて、半導体層形成後、下記に記載の構成を設けた以外は同様にして、薄膜トランジスタ素子シート３を作製した。
【０１６４】
（中間層の形成）：ＰＶＡ層（厚さ０．３μｍ）を設ける
有機半導体層３の上に、十分に精製を行ったポリビニルアルコールを超純粋製造装置で精製された水に溶解した水溶液を用いて塗設し、窒素ガス雰囲気中１００℃にて、よく乾燥させ、ポリビニルアルコールからなる中間層を形成した。
【０１６５】
（流動性電極材料反発領域６、Ａ、Ｂの形成）
さらに、中間層上に下記の組成物２をアイソパーＥ”（イソパラフィン系炭化水素、エクソン化学（株）製）単独溶媒で希釈した液体を、インクジェット法によりインク液滴を吐出した後、乾燥・硬化して、幅７μｍ、厚さ０．４μｍのシリコーンゴム層からなる流動性電極材料反発領域（層）６、Ａ，Ｂを形成した。
【０１６６】
（組成物２の組成）
α，ω−ジビニルポリジメチルシロキサン
（分子量約６０，０００） １００部
ＨＭＳ−５０１（両末端メチル（メチルハイドロジェンシロキサン）
（ジメチルシロキサン）共重合体、ＳｉＨ基数／分子量＝
０．６９モル／ｇ、チッソ（株）製） ７部
ビニルトリス（メチルエチルケトキシイミノ）シラン ３部
ＳＲＸ−２１２（白金触媒、東レ・ダウコーニングシリコーン（株）製）
５部
更に、流動性電極材料反発領域６、Ａ，Ｂが設けられている領域以外の中間層を水処理等により除去し、よく超純水で濯いだ。
【０１６７】
以降、実施例１と同様に電極材料を供給し２層の電極とした。
以上の工程により、本発明のＴＦＴシートが製造され、良好に駆動することができる。
【０１６８】
本発明の製造方法は、従来の素子シートの製造方法に比べて、極めて生産効率が高く（ソース電極とドレイン電極のショート現象等がない）、且つ、トランジスタ特性も高い素子シートが簡便に得られた。
【０１６９】
また、本発明の薄膜トランジスタ素子シートの作製方法では、有機半導体層からなるチャネル領域に形成される、ソース電極、ドレイン電極等は流動性電極材料反発領域を跨ぐようにパターン形成するだけでよく、例えば、図２（ａ）〜（ｃ）で示したように、インクジェット法により吐出された流動性電極材料は、流動性電極材料反発領域上で自動的に分断されて、所定の領域に供給され、ソース電極、ドレイン電極が形成されることも特徴の一つである。
【０１７０】
このように、従来公知のような極めて高い位置精度（パターン精度）が要求される、ソース電極、ドレイン電極の形成手段と比べて、電極材料形成の為のパターン精度が低くとも、電極材料反発領域を跨ぐ条件さえ、満たされれば、薄膜トランジスタが形成できることが判る。
【０１７１】
以上から、本発明の薄膜トランジスタの作製方法では、ＴＦＴのチャネル長は形成した皮膜の幅、すなわち、インクジェットの液滴の容量や吐出量（描き込み密度）で一意に制御でき、ソース電極、ドレイン電極（ＳＤ電極ともいう）がショートすることが効果的に防止でき、且つ、極めて簡単な方法で、精度が高く信頼性の高いＴＦＴ素子を、安定的に作製できることがわかる。
【０１７２】
更には、塗布等の簡単な方法で、ソース電極、ドレイン電極、画素電極、ソースバスライン等が形成できる。
【０１７３】
【発明の効果】
本発明により、高度の真空系や複雑なフォトリソ技術を用いなくとも、精度の高い有機薄膜トランジスタ素子シートを、簡便、且つ、効率的に製造する方法を提供することが出来た。また、素子の性能バラツキを低減して製造安定性の高い有機薄膜トランジスタ素子シートの作製方法が提供でき、更に、フィルムなどの樹脂支持体にも対応できる高精度な位置合わせが不要な薄膜トランジスタ素子シートを提供することが出来た。
【図面の簡単な説明】
【図１】本発明の薄膜トランジスタ素子のボトムゲート型の層構成例の一例を示す。
【図２】本発明の薄膜トランジスタ素子シートの一画素を形成する有機薄膜トランジスタの一態様を示す模式図である。
【図３】インクジェット法による、本発明の薄膜トランジスタ素子の作製工程の一態様を示す模式図である。
【図４】流動性電極材料反発領域がライン状に形成されている一例を示す。
【図５】流動性電極材料反発領域をライン状に形成されている一例を示す。
【図６】流動性電極材料反発領域をライン状に形成されている一例を示す。
【図７】流動性電極材料反発領域をライン状に形成されている一例を示す。
【図８】薄膜トランジスタ素子の作製方法を説明するための図である。
【符号の説明】
１ 支持体
２ ゲート電極
２ａ ゲート
３ 有機半導体層
３ａ 中間層
４ ドレイン電極
４ａ 画素電極
５ ソース電極
６ 流動性電極材料反発領域（層）
７ 受容層
８、８ａ、８ｂ インク液滴
１０ 薄膜トランジスタシート
１１ ゲートバスライン
１２ ソースバスライン[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thin film transistor element sheet and a method for manufacturing a thin film transistor element sheet.
[0002]
[Prior art]
With the spread of information terminals, needs for flat panel displays as displays for computers are increasing. In addition, with the progress of computerization, information provided in the form of paper has been provided electronically, and the number of opportunities to provide the information has increased, and electronic paper or digital media has become a thin, light, and portable mobile display medium. The need for paper is also growing.
[0003]
Generally, in a flat panel display device, a display medium is formed using elements utilizing liquid crystal, organic EL, electrophoresis, or the like. Further, in such display media, in order to ensure uniformity of screen luminance and screen rewriting speed, a technique using an active driving element constituted by a thin film transistor (TFT) as an image driving element has become mainstream.
[0004]
Here, a TFT element is usually formed by forming a semiconductor thin film such as a-Si (amorphous silicon) or p-Si (polysilicon) or a metal thin film such as a source, a drain or a gate electrode on a glass substrate. It is manufactured by forming sequentially. The manufacture of a flat panel display using this TFT usually requires a high-precision photolithography process in addition to a vacuum system such as CVD and sputtering, and a thin film formation process requiring a high-temperature treatment process. The load is very large. Furthermore, with the recent demand for larger screens of displays, their costs have become extremely enormous.
[0005]
In recent years, research and development of an organic TFT element using an organic semiconductor material has been actively pursued as a technique to compensate for the disadvantages of the conventional TFT element (see Patent Document 1, Non-Patent Document 1, etc.). Since this organic TFT element can be manufactured by a low-temperature process, it is said that a light and hard-to-break resin substrate can be used, and that a flexible display using a resin film as a support can be realized (Non-patented). Reference 2). In addition, by using an organic semiconductor material that can be manufactured by a wet process such as printing or coating under atmospheric pressure, a display with excellent productivity and extremely low cost can be realized.
[0006]
Also, a technique of an organic TFT using an inkjet for forming an electrode is disclosed (for example, see Patent Document 2), and a process without using a vacuum system is possible. Still, a polyimide film formed by photolithography is used.
[0007]
Since these use photolithography, complicated steps are required and the manufacturing cost is likely to be high.The accuracy of channel formation depends on the accuracy of photolithography and the position accuracy of ink jet drawing. In addition, since the liquid material is discharged to form the SD electrodes, they are likely to be short-circuited. If the short-circuit occurs, no element is formed.
[0008]
On the other hand, the technology of an organic TFT which claims advantages such as a non-vacuum system and a low-temperature process has been studied, but such a situation has not been solved as in the conventional TFT manufacturing method. It is generally said that the organic semiconductor layer can be formed by a low-temperature process, so that a TFT sheet can be formed on a resin support such as a film. There is a problem that the dimensional accuracy and the position accuracy are significantly reduced as compared with the conventional method.
[0009]
The present invention solves these problems.
[0010]
[Patent Document 1]
JP-A-10-190001
[0011]
[Patent Document 2]
WO 01/47043 pamphlet
[0012]
[Non-patent document 1]
Advanced Material 2002, Issue 2, p. 99 (review)
[0013]
[Non-patent document 2]
SID $ 02 Digest p57
[0014]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for easily and efficiently producing a high-precision thin film transistor element sheet without using a vacuum system or photolithography. It is an object of the present invention to provide a method for producing an organic thin film transistor element sheet having high production stability by reducing the performance variation of the thin film transistor. A third object of the present invention is to provide a thin film transistor element sheet produced by the above method. . Further, a third object of the present invention is to provide a thin film transistor element sheet which does not need high-precision alignment and can be applied to a resin support such as a film.
[0015]
[Means for Solving the Problems]
The above object of the present invention has been achieved by the following constitutions 1 to 12.
[0016]
1. A thin film transistor element sheet in which a plurality of thin film transistor elements each having a gate electrode, a gate insulating layer, a channel region including a semiconductor layer, a source electrode and a drain electrode are connected to a support through a gate bus line and a source bus line. In the method for producing
Forming a flowable electrode material repulsion region on the channel region or on the support, directly or through another layer, and then the flowable electrode material is deposited on the channel region or on the support, A method for manufacturing a thin film transistor element sheet, comprising a step of supplying at least the source electrode and the drain electrode supplied directly or through another layer.
[0017]
2. 2. The method for manufacturing a thin film transistor element sheet according to the item 1, wherein the channel region intersects a gate bus line.
[0018]
3. 3. The method for manufacturing a thin film transistor element sheet according to 1 or 2, wherein the support is a resin substrate.
[0019]
4. The fluid electrode material is supplied on a fluid electrode material repulsion area, and the fluid electrode material is divided on the repulsion area to form a source electrode and a drain electrode. The method for producing a thin film transistor element sheet according to any one of the above.
[0020]
5. The drain electrode forms a pixel electrode, or the drain electrode is connected to the pixel electrode, and the pixel electrode and the source bus line are separated by a fluid electrode material repulsion region. 5. The method for producing a thin film transistor element sheet according to any one of the above 1 to 4.
[0021]
6. The method for producing a thin film transistor element sheet according to any one of the above items 1 to 5, wherein the fluid electrode material is supplied by ink jet.
[0022]
7. 7. The method for producing a thin film transistor element sheet according to any one of items 1 to 6, wherein, after the step of forming the fluid electrode material repulsion region, the fluid electrode material is supplied to the entire surface of the sheet.
[0023]
8. The method for producing a thin film transistor element sheet according to any one of the above items 1 to 7, wherein the semiconductor layer contains an organic semiconductor material.
[0024]
9. 9. The method for manufacturing a thin film transistor element sheet according to any one of the above items 1 to 8, wherein the formation of the semiconductor layer is performed by inkjet.
[0025]
10. The method for manufacturing a thin film transistor element sheet according to any one of the above items 1 to 9, wherein the method is performed while transporting the support.
[0026]
11. 11. The thin film transistor element sheet according to any one of 1 to 10, wherein the fluid electrode material repulsion region is formed in a line while the support is transported in a direction intersecting with a gate bus line. Method.
[0027]
12. 12. A thin film transistor element sheet manufactured by the manufacturing method according to any one of 1 to 11 above.
[0028]
Hereinafter, the present invention will be described in detail.
As a result of various studies of the problems described above, the present inventors have found that a thin film transistor element having a gate electrode, a gate insulating layer, a channel region including a semiconductor layer, a source electrode, and a drain electrode on a support has a gate bus line. Forming a plurality of connected thin film transistor element sheets via a source bus line, a step of forming a fluid electrode material repulsion region on the channel region, and then, forming the fluid electrode material on the channel region; Is supplied to, at least the source electrode and the drain electrode are formed on the thin film transistor element sheet is formed using a conventional method without using a photolithography that requires sophisticated vacuum equipment and complicated processing steps. In addition, a highly accurate thin film transistor element sheet can be easily and efficiently manufactured. It is an epoch-making method.
[0029]
Further, the method for producing a thin film transistor element sheet of the present invention is a production method in which there is little variation in the performance of the obtained transistor element, and not only productivity but also production stability are high.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to an example of an organic thin film transistor element sheet, which is one mode of the thin film transistor element sheet of the present invention, with reference to the drawings.
[0031]
The thin film transistor element sheet of the present invention is roughly classified into a bottom gate type and a top gate type. The bottom gate type refers to a structure in which a gate electrode is provided over a support, directly or through another layer such as an undercoat layer, and then a source electrode and a drain are connected to each other by an organic semiconductor layer through a gate insulating layer. It has a layer configuration composed of electrodes.
[0032]
In addition, the top gate type has a layer structure in which a source electrode and a drain electrode which are in contact with an organic semiconductor layer are provided over a support and a gate electrode is provided thereover with a gate insulating layer interposed therebetween.
[0033]
The specific layer structure of the organic thin film transistor element sheet of the present invention will be described with reference to FIGS.
[0034]
FIG. 1 is an example of a bottom gate type layer configuration example.
In FIG. 1, a gate electrode 2 is provided on a support 1, a gate insulating layer 2a is provided on the gate electrode 2, an organic semiconductor layer 3 is provided on the gate insulating layer 2a, and an intermediate layer 3a is provided on the organic semiconductor layer 3. Is provided, a fluid electrode material repulsion region 6 having electrode material repulsion is provided, and a source electrode 5 and a drain electrode 4 are provided on both sides of the fluid electrode material repulsion region 6, respectively.
[0035]
Although not shown in the drawings, an undercoat layer is provided between the support 1 and the gate electrode 2, and an anodic oxidation treatment is performed before the gate insulating layer 2a is provided on the gate electrode 2. An anodic oxide film is formed on the gate electrode 2.
[0036]
Here, the intermediate layer 3a is provided in order to reduce the chemical and physical influence from the material forming the fluid electrode material repulsion region 6.
[0037]
After a semiconductor layer is formed in a bottom gate type configuration, which is generally used as a conventional TFT element for a display and has a high use value, a source electrode and a drain electrode are organically formed by a photolithographic method (including an etching method and a lift-off method). In the case of manufacturing a TFT, the organic semiconductor layer is affected by the coating solvent used, the developing solution component, the etching solution component, and the like in a photoresist material coating process, a photoresist layer developing process, and an electrode etching process. There is a problem of deterioration.
[0038]
On the other hand, in the present invention, since there is no step of using the photolithographic method at the time of manufacturing the source electrode 5 and the drain electrode 4, there is no deterioration of the organic semiconductor layer due to a photoresist material, a solvent or the like. is there.
[0039]
In a conventional TFT process, components such as a source electrode, a drain electrode, a pixel electrode, and a source bus line are formed by a photolithographic method using a photomask. Alignment is required. According to the present invention, it is not necessary to align the components, and the efficiency can be greatly improved. In particular, when a resin support such as a film is used, there is a problem in that the position accuracy between the components is reduced due to expansion and contraction of the film, and the alignment becomes impossible. Breakthrough in point.
[0040]
It is preferable that a channel region (also referred to as a layer) including a semiconductor layer constituting the thin film transistor element of the present invention is provided so as to intersect with a gate bus line constituting the element. Here, “intersect” includes a state where the gate bus line and the channel region formed of the semiconductor layer are in contact with each other.
[0041]
Next, some preferred embodiments will be described with reference to FIG.
FIG. 2 is a schematic diagram showing one embodiment of an organic thin film transistor forming one pixel of the thin film transistor element sheet of the present invention.
[0042]
In the thin-film transistor element shown in FIG. 2A, the gate bus line 11 (here, the gate bus line 11 is covered with a gate insulating layer (not shown), and therefore its existence position is indicated by a dotted line. ), An organic semiconductor layer 3 is provided so as to intersect, and a fluid electrode material repulsion region 6 (also referred to as a layer) is provided on the organic semiconductor layer 3. A drain electrode 4 and a source electrode 5 are provided on both sides. Here, the gate bus line 11 has a configuration also serving as a gate electrode.
[0043]
FIG. 2B is different from FIG. 2A in that the gate electrode is branched from the gate bus line 11. The organic semiconductor layer 3 is disposed on a gate electrode branched from the gate bus line 11, a source electrode 5 and a drain electrode are disposed in contact with the organic semiconductor layer 3, and a pixel electrode 4 a is formed on the drain electrode 4. However, the elementary electrode 4a may also serve as the drain electrode 4.
[0044]
FIG. 2C is a schematic diagram showing that a source electrode, a drain electrode, and a pixel electrode are formed from two inkjet dots. After the fluid electrode material repulsion region 6 and the source bus line 12 are formed, a droplet of the fluid electrode material is ejected to the organic semiconductor layer 3 and the fluid electrode material repulsion region 6 formed thereon. The fluid electrode material is self-organized on 6. Therefore, both the source electrode and the drain electrode are formed by one droplet, and the source electrode is joined to the source bus line. Similarly, the pixel electrode is formed from one inkjet droplet and is joined to the drain electrode. Here, the pixel electrode is separated from the source electrode and the source bus line 12 by the fluid electrode material repulsion region 6, and a short circuit is prevented. Each of the liquid droplets of the fluid electrode material described above may be controlled to an arbitrary amount in accordance with a desired size of the electrode that can be finally formed. For example, in order to further increase the size of the pixel electrode, it is possible to form a simple electrode by increasing the size of the droplet for the pixel electrode and discharging the droplet to a desired position by inkjet.
[0045]
《Fluid electrode material repulsion area》
The fluid electrode material repulsion region according to the present invention will be described.
[0046]
In the present invention, the fluid electrode material repulsion region is a region (also referred to as a layer) having a performance of repelling an electrode material to be an electrode (specifically, a source electrode or a drain electrode), When the thin film transistor is a bottom gate type, the thin film transistor is formed on an organic semiconductor layer, and when the thin film transistor is a top gate type, the thin film transistor is formed by patterning directly on a support or via another layer (such as an undercoat layer). Things.
[0047]
In the present invention, as a means for performing patterning, any means can be used as long as it can perform patterning, but from the viewpoint of minimizing the influence on the organic semiconductor layer, printing or the like is preferable. Is preferable, and among them, an ink jet method is particularly preferable.
[0048]
As the inkjet method, a known inkjet method such as a piezo method can be used, but from the viewpoint of drawing a fine pattern, an electrostatic suction type inkjet method is preferable.
[0049]
Here, when the fluid electrode material repulsion region is formed by an inkjet method, it is preferable to provide an ink receiving layer from the viewpoint of adjusting the formation region by ink ejection to an appropriate size. The droplets are absorbed by the ink receiving layer and dried or cured after being held, whereby the spread of the droplets can be suppressed.
[0050]
Although details of the ink receiving layer will be described later, a void type receiving layer used in a conventionally known ink jet recording medium is preferably used.
[0051]
As the fluid electrode material repulsion region (layer), any material having a performance of repelling the electrode material may be used, but Japanese Patent Application Laid-Open Nos. 9-292703 and 9-292703 may be used. 319075, JP-A-10-244773, JP-B-54-26923, JP-B-56-23150, JP-B-61-614, JP-A-8-82921, and JP-A-10-319579. JP, JP-A-2000-275824, JP-A-2000-330268, JP-A-2001-201849, JP-A-2001-249445, JP-A-2001-324800, JP-A-2002-229189, JP-A-4-324865, JP-A-5-53318, JP-A-5-257269, JP-A-6-89 No. 23, JP-A-7-199454, JP-A-8-328240, JP-A-9-62001, JP-A-9-120157, JP-A-11-30852, JP-A-2001-188339 JP-A-2001-343741, JP-A-2002-131894, and a forming material such as a so-called waterless flat plate ink repellent layer described in JP-A-2002-268216 can be used. Is preferably a silicone rubber layer or the like. Alternatively, a silane coupling agent, a titanate coupling agent, a silicone polymer adhesive, or the like may be used. In addition, when an electrode material using a solvent containing water as a main component is used, a lipophilic material such as a phenol resin or an epoxy resin may be used.
[0052]
Also, super-water-repellent materials such as those shown in SCIENCE magazine, vol. 299, p. 1377 can be used.
[0053]
The repulsion region of the fluid electrode material according to the present invention preferably has a light transmittance of 10% or less, more preferably 1% or less. Thus, deterioration of characteristics of the organic semiconductor layer due to light can be suppressed.
[0054]
Here, the light transmittance indicates an average transmittance in a wavelength region where photo-generated carriers can be generated in the organic semiconductor layer. Generally, it is preferable to have a performance of blocking light of 350 to 750 nm.
[0055]
In addition, since this technique is intended to suppress the light reaching the organic semiconductor layer in order to suppress the deterioration of the organic semiconductor layer due to light, it not only reduces the light transmittance in the fluid electrode material repulsion region, but also The light transmittance of other layers (all layers in the case of a multi-layer) such as an intermediate layer and a receiving layer which can be formed on the organic semiconductor layer may be 10% or less, and may be 1% or less. Is more preferable.
[0056]
In order to lower the light transmittance of the layer, a method of including a coloring material such as a pigment or a dye or an ultraviolet absorber in the layer can be used.
[0057]
<< Fluid electrode material: constituent materials for source electrode, drain electrode, etc. >>
In the production of the thin film transistor element sheet of the present invention, the fluid electrode material shown below is supplied to the fluid electrode material repulsion region, and the fluid electrode material is divided in the fluid electrode material repulsion region, whereby the fluidity is reduced. A source electrode and a drain electrode are formed on both sides of the electrode material repulsion region, respectively.
[0058]
The fluid electrode material according to the present invention is, specifically, a conductive material shown below, a solution, a paste, an ink, a metal thin film precursor material, a liquid dispersion, and the like. As a method of forming the source electrode and the drain electrode by supplying the fluid electrode material on the repulsive region, various methods used for manufacturing an organic semiconductor layer described later, for example, a coating method and an inkjet method can be applied. is there.
[0059]
Here, when the source electrode and the drain electrode are formed by discharging the ink containing the fluid electrode material onto the fluid electrode material repelling region by the ink jet method, the viewpoint of adjusting the electrode formation region by ink ejection to an appropriate size. Therefore, it is preferable to provide an ink receiving layer. As the ink receiving layer, a void type receiving layer used in a conventionally known ink jet recording medium is preferably used.
[0060]
Further, when performing electrode formation using the fluid electrode material according to the present invention, in order to improve the wettability with a semiconductor layer or a coating substrate, if necessary, a known surfactant or an organic solvent is added. Is also good.
[0061]
Here, one embodiment of a manufacturing process of a thin film transistor element of the present invention by an ink-jet method is described with reference to FIGS. In FIG. 3, the fabrication of the fluid electrode material repulsion region 6, the source electrode 5, the drain electrode 4, and the source bus line 12 will be described.
[0062]
In FIG. 3, first, a channel region (layer) made of the organic semiconductor layer 3 is provided so as to cross the gate bus line 11 also serving as a date electrode, and after the above-mentioned fluid electrode material repulsion region (layer) 6 is formed, An ink composed of a dispersion or a solution containing a fluid electrode material is supplied to both sides of the fluid electrode material repulsion area 6 or supplied on the repulsion area 6 to separate the fluid electrode material, An electrode 5, a drain electrode 4, and a pixel electrode are formed.
[0063]
In forming the fluid electrode material repulsion region 6, a compound that forms an insulating region is preferably used, and among them, the material that forms the above-described electrode material repulsion layer is preferably used.
[0064]
The source bus line 12 is similarly formed by the ink jet method. If the source bus line is formed before the formation of the source electrode, undesired spread of the droplet of the source electrode material is suppressed.
[0065]
When a fluid electrode material is ejected using an inkjet method, an ink containing a conductive material is usually prepared. However, a solvent or a dispersion medium used for the ink may cause damage to an organic semiconductor (organic semiconductor layer). It is preferable to select a material as small as possible. Although the damage depends on the semiconductor material, for example, when pentacene is used, it is preferable that water be contained in an amount of 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 90% by mass or more. The solvent or dispersion medium contained.
[0066]
Alternatively, a transparent conductive film or the like formed from the above materials can be used.
Here, “transparent” means that the light transmittance (as light, from ultraviolet light to visible light) is at least 50% or more, and preferably 80% or more.
[0067]
In the method of manufacturing a thin film transistor element sheet according to the present invention, after forming the above-mentioned fluid electrode material repulsion region on the sheet as shown in FIGS. 4 to 7, a step of supplying the fluid electrode material to the entire surface of the sheet is performed. An element sheet can be manufactured in one step or two steps, and a manufacturing method with extremely high production efficiency can be provided as compared with the manufacturing of an element sheet that requires many stages of conventional advanced photolithography technology. I understood. In addition, the obtained element sheet has a high performance of the transistor element, and is an epoch-making method in terms of its meaning.
[0068]
In supplying the flowable electrode material to the entire surface of the sheet, a method preferably used is an ink jet method, but in applying the ink jet method, it is preferable to perform the method while transporting the support of the thin film transistor element, and more preferably, While the support is transported in a direction crossing the gate bus line, a fluid electrode material repulsion area is formed in a line shape, and then the fluid electrode material is supplied to form a source electrode, a drain electrode, a source bus line, and the like. Is preferred. Further, it is preferable to form a pixel electrode and the like at the same time as forming the drain electrode.
[0069]
Here, one mode of forming the fluid electrode material repulsion region in a line on the element sheet will be described with reference to FIGS.
[0070]
In FIG. 4, the organic semiconductor layer 3 is provided so as to intersect with the gate bus line 11, and is formed by, for example, an inkjet method for discharging a solution or dispersion of the organic semiconductor material. Next, while the support (not shown) is conveyed in a direction intersecting with the gate bus line 11, the fluid electrode material repulsion region 6 is formed in a line shape.
[0071]
A preferred method of forming the fluid electrode material repulsion region 6 in a line shape (also referred to as a line pattern) is a method of patterning by printing or an inkjet method.
[0072]
The channel region is formed by the lines of the fluid electrode material repulsion region 6 formed on the element sheet, and the regions 20 and 21 are respectively formed by forming the lines A and B at the same time. The lines A and B are not essential requirements. For example, electrodes may be formed as shown in FIG. 2 (c) and FIG.
[0073]
In the manufacture of the thin film transistor element sheet of the present invention, in FIG. 4, the fluid electrode material is supplied to the region 20, the source electrode and the source bus line are formed, the fluid electrode material is supplied to the region 21, and the drain electrode and the pixel electrode are formed. Is formed. Further, the region 21 forms a storage capacitor with the adjacent gate bus line.
[0074]
In FIG. 4, the gate bus line also serves as a gate electrode. With this configuration, even if the semiconductor layers 6, 6, A, and B of each pixel are displaced in the gate bus line direction, the TFT sheet can be formed without any problem. Manufactured.
[0075]
Incidentally, the material forming the source electrode and the source bus line may be the same or different. Here, when the materials constituting the source electrode and the source bus line are different, the source bus line constituting material may be supplied after the source electrode constituting material is supplied onto the element sheet, or vice versa. Alternatively, the source electrode forming material and the source bus line forming material may be simultaneously provided on the sheet.
[0076]
FIG. 5 has the same configuration as FIG. 4 except that the channel region made of the organic semiconductor layer 3 is formed in a line of the fluid electrode material repulsion region 6. The organic semiconductor layer 3 and the fluid electrode material repulsion region 6 are efficiently manufactured by, for example, continuous jetting ink jetting, preferably by drawing from a multi-nozzle head having fixed nozzles and a fixed interval.
[0077]
FIG. 6 is the same as FIG. 4 except that a gate electrode is formed by branching off from the gate bus line 11 and a channel region made of the organic semiconductor layer 3 is provided on the comb-shaped protrusion.
[0078]
FIG. 7 is the same as FIG. 6 except that a capacitor line 22 is provided to face the gate bus line 11.
[0079]
4 to 7, as a constituent material of a source electrode, a drain electrode, and a source bus line, a conductive paste (or ink) mainly containing a conductive polymer or metal fine particles, for example, polystyrene sulfonic acid and poly An aqueous dispersion of (ethylenedioxythiophene) (Baytron P, manufactured by Bayer), an aqueous dispersion of silver paste, or an aqueous dispersion of metal fine particles described in JP-A-11-80647 are preferably used. In particular, a highly conductive metal material is preferable as a constituent material of the source bus line.
[0080]
(Conductive material)
The conductive material is not particularly limited as long as it has a conductivity at a practical level as an electrode, and is not particularly limited. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium , Tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, tin / antimony oxide, indium tin oxide (ITO), fluorine-doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, Lithium, beryllium, sodium, magnesium, potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloys, magnesium, lithium, aluminum, magnesium / copper mixtures, Nesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, lithium / aluminum mixture and the like are used, and platinum, gold, silver, copper, aluminum, indium, ITO and carbon are particularly preferable. .
[0081]
Further, as the conductive material, a conductive polymer, metal fine particles, or the like can be suitably used. As the dispersion containing metal fine particles, for example, a known conductive paste or the like may be used, but a dispersion containing metal fine particles having a particle diameter of 1 nm to 50 nm, preferably 1 nm to 10 nm is preferable.
[0082]
Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, zinc, etc. Can be used.
[0083]
It is preferable to form an electrode using a dispersion in which fine particles composed of these metals are dispersed in water or a dispersion medium that is any organic solvent using a dispersion stabilizer mainly composed of an organic material.
[0084]
As a method for producing such a dispersion of fine metal particles, a metal ion is reduced in a liquid phase, such as a physical generation method such as a gas evaporation method, a sputtering method, and a metal vapor synthesis method, and a colloid method and a coprecipitation method. Chemical production methods for producing metal fine particles by the method described above are preferred, and are preferably described in JP-A-11-76800, JP-A-11-80647, JP-A-11-319538 and JP-A-2000-239853. Colloid method, JP-A-2001-254185, JP-A-2001-53028, JP-A-2001-35255, JP-A-2000-124157, and JP-A-2000-123634, by a gas evaporation method. It is a dispersion of the produced metal fine particles. The electrodes and the circuit are formed using these metal fine particle dispersions, and after the solvent is dried, if necessary, heated to a shape in the range of 100 ° C to 300 ° C, preferably 150 ° C to 200 ° C. Thereby, the metal fine particles are thermally fused to form an electrode pattern and a circuit pattern having a desired shape.
[0085]
Further, as the source electrode and the drain electrode, it is also preferable to use a known conductive polymer whose conductivity has been improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, conductive polythiophene, polyethylene dioxythiophene, and polystyrene. Sulfonic acid complexes and the like are also suitably used. Thereby, the contact resistance between the source electrode, the drain electrode, and the organic semiconductor layer can be reduced.
[0086]
In the present invention, the above-mentioned patterning method of the source electrode, the drain electrode and the like is capable of patterning the source electrode and the drain electrode by supplying the fluid electrode material to the fluid electrode material repulsion region having electrode material repulsion. Anything can be used.
[0087]
《Constituent material of gate electrode》
As the constituent material of the gate electrode according to the present invention, the same material as the constituent material of the source electrode and the drain electrode can be used.
[0088]
《Ink receiving layer》
The ink receiving layer according to the invention will be described.
[0089]
Fluid electrode material repelling region having electrode material repellency according to the present invention, or a fluid electrode material was ejected to the fluid electrode material repelling region using an ink jet nozzle, and was cut on the fluid electrode material repelling region. As a method for forming a source electrode and a drain electrode formed of a fluid electrode material, a material for forming a fluid electrode material repulsive region, a solution or a dispersion containing a material for forming a source electrode and a drain electrode, or the like is directly inkjet-processed. It is preferable to form a pattern on the ink receiving layer by the following method.
[0090]
Here, the ink receiving layer is preferably a void type, and the void type is obtained by applying a mixture of fine particles and a water-soluble binder.
[0091]
Examples of the fine particles that can be used in the ink receiving layer include inorganic fine particles and organic fine particles. In particular, inorganic fine particles are preferable because they are easily obtained. Examples of such inorganic fine particles include light calcium carbonate, heavy calcium carbonate, magnesium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc hydroxide, zinc sulfide, zinc carbonate, White inorganic pigments such as hydrotalcite, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, pseudoboehmite, aluminum hydroxide, lithopone, zeolite, magnesium hydroxide, etc. Can be mentioned. The inorganic fine particles can be used as they are as primary particles or in a state where secondary aggregated particles are formed.
[0092]
As the inorganic fine particles, alumina, pseudoboehmite, colloidal silica or fine particle silica synthesized by a gas phase method is preferable, and fine particle silica synthesized by a gas phase method is particularly preferable. The silica synthesized by this gas phase method may be one whose surface is modified with Al. The Al content of the fumed silica whose surface is modified with Al is preferably 0.05% to 5% by mass relative to silica.
[0093]
The particle diameter of the inorganic fine particles may be any particle diameter, preferably 1 μm or less, more preferably 0.2 μm or less, particularly preferably 0.1 μm or less. It is.
[0094]
Here, the lower limit of the particle size is not particularly limited, but is preferably approximately 0.003 μm or more, and particularly preferably 0.005 μm or more, from the viewpoint of production of the inorganic fine particles.
[0095]
The average particle diameter of the inorganic fine particles is obtained by observing the cross section and surface of the porous layer with an electron microscope, calculating the particle diameter of 100 arbitrary particles, and calculating the simple average value (number average). Here, each particle size is represented by a diameter assuming a circle equal to the projected area.
[0096]
The fine particles may be present in the porous film as primary particles or as secondary particles or higher-order aggregated particles, but the average particle size is determined by observation with an electron microscope. Refers to the particle size of what forms independent particles in the porous layer.
[0097]
The content of the fine particles in the water-soluble coating solution is preferably 5% by mass to 40% by mass, and particularly preferably 7% by mass to 30% by mass.
[0098]
The hydrophilic binder contained in the void-type receiving layer is not particularly limited, and a conventionally known hydrophilic binder can be used. For example, gelatin, polyvinylpyrrolidone, polyethylene oxide, polyacrylamide, and polyvinyl alcohol are used. However, polyvinyl alcohol is particularly preferred.
[0099]
Polyvinyl alcohol has an interaction with inorganic fine particles, is a polymer having a particularly high holding power for inorganic fine particles, and has a relatively small humidity dependence of hygroscopicity. Polyvinyl alcohol preferably used in the present invention includes, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol having a cationically modified terminal or anionic modified polyvinyl alcohol having an anionic group. Polyvinyl alcohol is also included.
[0100]
The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 300 or more, and particularly preferably has an average degree of polymerization of 1,000 to 5,000. The saponification degree is preferably from 70% to 100%, particularly preferably from 80% to 99.5%.
[0101]
As the cation-modified polyvinyl alcohol, for example, as described in JP-A-61-10483, a tertiary amino group or a quaternary ammonium group is contained in the main chain or side chain of the polyvinyl alcohol. Polyvinyl alcohol having a cationic group, which can be obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.
[0102]
Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl- (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl- (3-acrylamido-3,3-dimethylpropyl) ammonium chloride N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride, trimethyl- (3-methacrylamidopropyl) ammonium chloride, N- (1, 1-dimethyl-3-dimethylaminopropyl) acrylamide and the like.
[0103]
The ratio of the cation-modified group-containing monomer in the cation-modified polyvinyl alcohol is 0.1 mol% to 10 mol%, preferably 0.2 mol% to 5 mol%, based on vinyl acetate.
[0104]
The anion-modified polyvinyl alcohol is, for example, a polyvinyl alcohol having an anionic group described in JP-A-1-2060888, a vinyl alcohol described in JP-A-61-237681, and JP-A-63-307979. Copolymers of alcohols and vinyl compounds having a water-soluble group, and modified polyvinyl alcohols having a water-soluble group described in JP-A-7-285265 are exemplified.
[0105]
Further, as the nonionic modified polyvinyl alcohol, for example, a polyvinyl alcohol derivative in which a polyalkylene oxide group is added to a part of vinyl alcohol described in JP-A-7-9758, and described in JP-A-8-25795 And a block copolymer of a vinyl compound having a hydrophobic group and vinyl alcohol.
[0106]
Two or more kinds of polyvinyl alcohols having different degrees of polymerization and different types of modification can be used in combination. In particular, when using a polyvinyl alcohol having a degree of polymerization of 2,000 or more, a polyvinyl alcohol having a degree of polymerization of 1,000 or less is previously added to the inorganic fine particle dispersion in an amount of 0.05% by mass to 10% by mass, preferably, It is preferable to add polyvinyl alcohol having a degree of polymerization of 2000 or more after adding 0.1% by mass to 5% by mass, since there is no remarkable increase in viscosity.
[0107]
The ratio of the fine particles to the hydrophilic binder in the void-type receiving layer is such that the excess hydrophilic binder swells during ink jet recording and closes the voids while properly maintaining the porosity of the porous layer and maintaining a sufficient void volume. It is preferable that the mass ratio is 2 to 20 times, more preferably 2.5 times, from the viewpoint of preventing the occurrence of the conductive polymer, properly maintaining the absorption rate of the conductive polymer, and preventing the porous layer from cracking. It is twice to 12 times, particularly preferably 3 to 10 times.
[0108]
《Semiconductor layer》
The semiconductor layer according to the present invention can contain an inorganic or organic semiconductor material such as conventionally known amorphous silicon and polysilicon, but preferably contains an organic semiconductor material in the present invention.
[0109]
《Organic semiconductor materials》
As the organic semiconductor material according to the present invention, a π-conjugated material is used. For example, polypyrrole such as polypyrrole, poly (N-substituted pyrrole), poly (3-substituted pyrrole), and poly (3,4-disubstituted pyrrole) , Polythiophenes such as polythiophene, poly (3-substituted thiophene), poly (3,4-disubstituted thiophene), polybenzothiophene, polyisothianaphthenes such as polyisothianaphthene, and polyphenylenevinylene Poly (p-phenylenevinylene) s such as chenylenevinylenes and poly (p-phenylenevinylene), polyaniline, poly (N-substituted aniline), poly (3-substituted aniline), poly (2,3-substituted aniline) Such as polyaniline, polyacetylene such as polyacetylene, and polydiacetyl such as polydiacetylene. Polyazenes such as lenes, polyazulene, polypyrenes such as polypyrene, polycarbazoles, polycarbazoles such as poly (N-substituted carbazole), polyselenophenes such as polyselenophene, polyfurans such as polyfuran and polybenzofuran, Poly (p-phenylene) such as poly (p-phenylene), polyindole such as polyindole, polypyridazine such as polypyridazine, naphthacene, pentacene, hexacene, heptacene, dibenzopentacene, tetrabenzopentacene, pyrene, diene Polyacenes such as benzopyrene, chrysene, perylene, coronene, terylene, ovalen, quaterylene, circum anthracene, and a part of the carbon of the polyacenes are substituted with atoms such as N, S, O, and functional groups such as carbonyl groups. Derivatives (triphenodioxazine, triphenodithiazine, hexacene-6,15-quinone, etc.), polymers such as polyvinylcarbazole, polyphenylene sulfide, and polyvinylene sulfide, and polycyclic compounds described in JP-A-11-195790. Condensates and the like can be used.
[0110]
Further, for example, thiophene hexamer α-sexithiophene α, ω-dihexyl-α-sexithiophene, α, ω-dihexyl-α-quinkethiophene, α, ω-bis ( Oligomers such as 3-butoxypropyl) -α-sexithiophene and styrylbenzene derivatives can also be suitably used.
[0111]
Further, metal phthalocyanines such as copper phthalocyanine and fluorine-substituted copper phthalocyanine described in JP-A-11-251601, naphthalene 1,4,5,8-tetracarboxylic diimide, N, N'-bis (4-trifluoromethyl N, N′-bis (1H, 1H-perfluorooctyl), N, N′-bis (1H, 1H-perfluorobutyl) and N, N with benzyl) naphthalene 1,4,5,8-tetracarboxylic diimide '-Dioctylnaphthalene 1,4,5,8-tetracarboxylic diimide derivative, naphthalene tetracarboxylic diimides such as naphthalene 2,3,6,7 tetracarboxylic diimide, and anthracene 2,3,6,7-tetra Condensed ring tetrads such as anthracenetetracarboxylic diimides such as carboxylic diimides Carboxylic acid diimides, C₆₀, C₇₀, C₇₆, C₇₈, C₈₄Examples include fullerenes, carbon nanotubes such as SWNT, and dyes such as merocyanine dyes and hemicyanine dyes.
[0112]
Among these π-conjugated materials, thiophene, vinylene, chenylene vinylene, phenylene vinylene, p-phenylene, a substituted product thereof, or two or more of these are used as a repeating unit, and the number n of the repeating unit is 4 to 4. At least one selected from the group consisting of an oligomer having 10 or a polymer in which the number n of the repeating unit is 20 or more, a condensed polycyclic aromatic compound such as pentacene, a fullerene, a condensed ring tetracarboxylic diimide, and a metal phthalocyanine Species are preferred.
[0113]
Other organic semiconductor materials include tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTF-iodine complex, and TCNQ-iodine complex. , Etc. can also be used. Further, σ-conjugated polymers such as polysilane and polygermane, and hybrid organic / inorganic materials described in JP-A-2000-260999 can also be used.
[0114]
In the present invention, for example, a material having a functional group such as acrylic acid, acetamido, dimethylamino group, cyano group, carboxyl group, or nitro group in the organic semiconductor layer, a benzoquinone derivative, tetracyanoethylene, and tetracyanoquinodimethane And materials that are functional acceptors such as amino groups, triphenyl groups, alkyl groups, hydroxyl groups, alkoxy groups and phenyl groups, and substituted amines such as phenylenediamine. , Anthracene, benzoanthracene, substituted benzoanthracenes, pyrene, substituted pyrene, carbazole and its derivatives, tetrathiafulvalene and its derivatives, etc. Process Good.
[0115]
The doping means that an electron donating molecule (acceptor) or an electron donating molecule (donor) is introduced into the thin film as a dopant. Therefore, the doped thin film is a thin film containing the condensed polycyclic aromatic compound and the dopant. Known dopants can be used for the present invention.
[0116]
(Method of manufacturing organic semiconductor layer)
These organic semiconductor layers can be formed by vacuum deposition, molecular beam epitaxy, ion cluster beam, low energy ion beam, ion plating, CVD, sputtering, plasma polymerization, electrolytic polymerization, chemical polymerization, or the like. A polymerization method, a spray coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a roll coating method, a bar coating method, a die coating method, an ink jet method, an LB method, and the like can be used, and can be used depending on the material. However, from the viewpoint of productivity, spin coating, blade coating, dip coating, roll coating, bar coating, die coating, and ink jetting can be used to easily and precisely form thin films using organic semiconductor solutions. The law is preferred.
[0117]
As described in Advanced Material, 1999, No. 6, p. 480-483, when a precursor such as pentacene is soluble in a solvent, a precursor film formed by coating is heat-treated to obtain a desired organic compound. A thin film of a material may be formed.
[0118]
The thickness of the organic semiconductor layer made of such an organic semiconductor material is not particularly limited, but the characteristics of the obtained transistor often largely depend on the thickness of the organic semiconductor layer. Although it depends on the type of semiconductor material, it is generally preferably 1 μm or less, particularly preferably 10 nm to 300 nm.
[0119]
《Intermediate layer》
The organic thin film transistor, which is a preferred embodiment of the thin film transistor of the present invention, preferably has an intermediate layer in contact with the organic semiconductor layer. By providing the intermediate layer in contact with the organic semiconductor layer, deterioration of the organic semiconductor layer due to air or moisture can be suppressed. Further, by providing the intermediate layer, the durability due to bending or the like is also improved, so that a decrease in characteristics as a transistor can be suppressed.
[0120]
Also, depending on the type of the organic semiconductor material, the material forming the repellent region of the ink-repellent fluid electrode material and the solvent thereof, the damage to the organic semiconductor layer when forming the repellent region of the fluid electrode material is suppressed. Effect can be obtained.
[0121]
As the intermediate layer, a material that does not affect the organic semiconductor layer during or after the manufacturing process of the organic semiconductor transistor is selected.
[0122]
As such a material, a phenol resin such as polyvinylphenol or a novolak resin, an epoxy resin, a hydrophilic polymer, or the like can be used depending on the kind of the semiconductor material.
[0123]
The hydrophilic polymer is a polymer having solubility or dispersibility in water or an acidic aqueous solution, an alkaline aqueous solution, an alcohol aqueous solution, or an aqueous solution of various surfactants. For example, a homopolymer or copolymer composed of components such as polyvinyl alcohol, HEMA, acrylic acid, and acrylamide can be suitably used. Further, as other materials, a material containing an inorganic oxide or an inorganic nitride is also preferable because it does not affect the organic semiconductor and does not affect other application steps. Further, a material for a gate insulating layer described later can also be used.
[0124]
The intermediate layer containing an inorganic oxide or an inorganic nitride is preferably formed by an atmospheric pressure plasma method.
[0125]
A method of forming a thin film by a plasma method under atmospheric pressure is a process of forming a thin film on a substrate by discharging under an atmospheric pressure or a pressure near the atmospheric pressure, exciting a reactive gas by plasma, and forming a thin film on a substrate. JP-A-11-61406, JP-A-11-133205, JP-A-2000-121804, JP-A-2000-147209, JP-A-2000-185362 and the like (hereinafter also referred to as atmospheric pressure plasma method) Name). Thereby, a highly functional thin film can be formed with high productivity.
[0126]
《Gate insulating layer》
Various insulating films can be used as the gate insulating layer of the thin film transistor of the present invention. In particular, an inorganic oxide film having a high relative dielectric constant is preferable. As the inorganic oxide, silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Examples include barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate bismuth, and yttrium trioxide. Among them, preferred are silicon oxide, aluminum oxide, tantalum oxide and titanium oxide. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used.
[0127]
Examples of the method for forming the film include a vacuum deposition method, a molecular beam epitaxial growth method, an ion cluster beam method, a low energy ion beam method, an ion plating method, a CVD method, a dry process such as a sputtering method and an atmospheric pressure plasma method, and a spray method. Wet processes such as a coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a coating method such as a roll coating method, a bar coating method, a die coating method, and a patterning method such as printing or inkjet, Can be used depending on the material.
[0128]
The wet process is a method in which fine particles of an inorganic oxide are dispersed in an optional organic solvent or water using a dispersing aid such as a surfactant, if necessary, and a method of drying, or a method of drying an oxide precursor, for example, A so-called sol-gel method of applying and drying a solution of the alkoxide compound is used.
[0129]
Among these, the film formation by the atmospheric pressure plasma method or the anodic oxidation method is preferable.
[0130]
It is also preferable that the gate insulating layer is composed of an anodic oxide film or an anodic oxide film and an insulating film. The anodic oxide film is desirably subjected to a sealing treatment. The anodized film is formed by anodizing a metal capable of being anodized by a known method.
[0131]
Examples of the metal that can be anodized include aluminum and tantalum. The method of the anodization is not particularly limited, and a known method can be used. By performing the anodic oxidation treatment, an oxide film is formed. As the electrolyte used for the anodic oxidation treatment, any electrolyte can be used as long as it can form a porous oxide film. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, boric acid, sulfamic acid, benzene sulfone Acids or the like, or mixed acids obtained by combining two or more kinds thereof or salts thereof are used. Since the anodizing treatment conditions vary depending on the electrolytic solution used, they cannot be specified unconditionally, but generally, the concentration of the electrolytic solution is 1% by mass to 80% by mass, and the temperature of the electrolytic solution is 5 ° C to 70 ° C. , Current density 0.5A / dm²~ 60A / dm², A voltage of 1 V to 100 V and an electrolysis time of 10 seconds to 5 minutes are appropriate. A preferable anodic oxidation treatment is a method in which an aqueous solution of sulfuric acid, phosphoric acid, boric acid, tartaric acid, or the like or a salt thereof is used as an electrolytic solution and treatment is performed with a direct current, but an alternating current may be used. The concentration of these acids is preferably 5% by mass to 45% by mass, the temperature of the electrolytic solution is 20 ° C. to 50 ° C., and the current density is 0.5 A / dm.²~ 20A / dm²For 20 seconds to 250 seconds.
[0132]
As the organic compound film, polyimide, polyamide, polyester, polyacrylate, photo-radical polymerization type, photo-cationic polymerization type photo-curable resin, or copolymer containing acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolak resin, And cyanoethyl pullulan can also be used.
[0133]
As the method for forming the organic compound film, the wet process is preferable.
The inorganic oxide film and the organic oxide film can be laminated and used together. The thickness of these insulating films is generally 50 nm to 3 μm, preferably 100 nm to 1 μm.
[0134]
Arbitrary orientation treatment may be performed between the gate insulating layer and the organic semiconductor layer. A silane coupling agent, for example, octadecyltrichlorosilane, trichloromethylsilazane, or a self-assembled alignment film such as alkanephosphoric acid, alkanesulfonic acid, or alkanecarboxylic acid is preferably used.
[0135]
《Support》
The support according to the present invention will be described.
[0136]
As the support according to the present invention, a resin substrate (also simply referred to as resin) is preferable, and for example, a plastic film sheet can be used. Examples of the plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), polyether imide, polyether ether ketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), Examples include a film made of cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like. As described above, by using a plastic film, the weight can be reduced as compared with the case of using a glass substrate, portability can be improved, and resistance to impact can be improved.
[0137]
Further, a sealing film can be provided over the thin film transistor element. Examples of the sealing film include the above-described inorganic oxides and inorganic nitrides, and are preferably formed by the above-described atmospheric pressure plasma method. Thereby, the durability of the thin film transistor is improved.
[0138]
《Undercoat layer》
The thin film transistor element according to the present invention preferably has at least one of an undercoat layer containing a compound selected from inorganic oxides and inorganic nitrides and an undercoat layer containing a polymer.
[0139]
Examples of the inorganic oxide contained in the undercoat layer include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, and titanate. Examples include lead lanthanum, strontium titanate, barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth niobate tantalate, and yttrium trioxide. Examples of the inorganic nitride include silicon nitride and aluminum nitride.
[0140]
Among them, preferred are silicon oxide, aluminum oxide, tantalum oxide, titanium oxide and silicon nitride.
[0141]
In the present invention, the undercoat layer containing a compound selected from an inorganic oxide and an inorganic nitride is preferably formed by the above-mentioned atmospheric pressure plasma method.
[0142]
Examples of the polymer used for the undercoat layer containing a polymer include polyester resin, polycarbonate resin, cellulose resin, acrylic resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, phenoxy resin, norbornene resin, epoxy resin, and vinyl chloride-vinyl acetate. Copolymer, vinyl chloride resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer Coal, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, vinyl polymer such as ethylene-vinyl acetate copolymer, polyamide resin, ethylene-butadiene resin, Tajien - rubber-based resin such as acrylonitrile resin, silicone resin, and fluorine resins.
[0143]
【Example】
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.
[0144]
Example 1
As described below, a thin film transistor element sheet 1 having the configuration shown in FIGS.
[0145]
<< Preparation of thin film transistor element sheet 1 >>
Process (1)
A gate bus line 11 (a gate electrode is not particularly shown when the gate bus line also functions as a gate electrode) and an organic semiconductor layer 3 are provided on the support 1 as follows.
[0146]
(Preparation of support)
50 W / m on the surface of the support 1 made of a 200 μm thick PES film²/ Min, and a coating solution having the following composition was applied to a dry film thickness of 2 µm, dried at 90 ° C for 5 minutes, and then 4 seconds from a distance of 10 cm under a 60 W / cm high-pressure mercury lamp. Cured.
[0147]
Dipentaerythritol hexaacrylate monomer 60g
Dipentaerythritol hexaacrylate dimer 20g
Ingredient of dipentaerythritol hexaacrylate trimer or more 20 g
Diethoxybenzophenone UV initiator 2g
Silicone surfactant 1g
75 g of methyl ethyl ketone
75 g of methyl propylene glycol
Further, a 50 nm-thick silicon oxide film was continuously formed on the layer by the atmospheric pressure plasma treatment under the following conditions to form an undercoat layer (not shown).
[0148]
(Used gas)
Inert gas: 98.25% by volume of helium
Reactive gas: oxygen gas 1.5% by volume
Reactive gas: tetraethoxysilane vapor (bubble with helium gas) 0.25% by volume
(Discharge conditions)
Discharge output: 10 W / cm²
(Electrode conditions)
The electrode was coated with a 1 mm-thick ceramic spray-coated alumina on a stainless steel jacket roll base material having cooling means with cooling water, then coated with a solution of tetramethoxysilane diluted with ethyl acetate, dried, and sealed with ultraviolet irradiation. This is a roll electrode having a dielectric (relative dielectric constant: 10) which is subjected to a hole treatment to make the surface smooth and the surface roughness (Rmax) specified in JIS B 0601 to be 5 μm, and is grounded. . On the other hand, as an application electrode, a hollow rectangular stainless steel pipe was coated with the same dielectric as described above under the same conditions.
[0149]
(Gate electrode formation step)
On the undercoat layer, a photosensitive resin 1 having the following composition was applied and dried at 100 ° C. for 1 minute to form a photosensitive resin layer having a thickness of 2 μm.
(Photosensitive resin 1)
Dye A 7 parts
90 parts of novolak resin (novolak resin obtained by co-condensing phenol with m- and p-mixed cresol and formaldehyde (Mw = 4000, phenol / m-cresol / p-cresol molar ratio is 5/57/38, respectively)) 90 parts
Crystal violet 3 parts
[0150]
Embedded image

[0151]
200 mJ / cm for a semiconductor laser with an oscillation wavelength of 830 nm and an output of 100 mW²After exposing the pattern of the gate bus line and the gate electrode at an energy density of, the resist image was obtained by developing with an alkaline aqueous solution.
[0152]
Further, an aluminum film having a thickness of 300 nm was formed on the entire surface by a sputtering method, and the remaining portion of the photosensitive resin layer was removed with MEK, thereby producing a gate bus line 11 and a gate electrode. .
[0153]
(Anodic oxide film formation process)
After thoroughly washing the above film substrate, an anodic oxide film (not shown) was prepared in a 50 g / L aqueous ammonium borate solution for 5 minutes using a direct current supplied from a constant voltage power supply of 100 V. Washed well with ultrapure water.
[0154]
(Gate insulating layer forming step)
Further, at a film temperature of 200 ° C., the gas used in the above-mentioned atmospheric pressure plasma method was changed as follows, and a gate insulating layer (not shown) as a silicon oxide layer having a thickness of 30 nm was provided.
[0155]
(Used gas)
Inert gas: 98.25% by volume of helium
Reactive gas: oxygen gas 1.5% by volume
Reactive gas: tetraethoxysilane vapor (bubble with helium gas) 0.25% by volume
(Organic semiconductor layer forming step)
Next, on a gate insulating layer (not shown), a chloroform solution of the following compound C is discharged to a region where a channel is to be formed using a piezo-type inkjet method, and the solution is heated at 50 ° C. in a nitrogen gas. And heat-treated at 200 ° C. for 10 minutes to form an organic semiconductor layer 3 which is a pentacene thin film having a thickness of 50 nm.
[0156]
Embedded image

[0157]
Step (2): Formation of Fluid Electrode Material Repulsion Regions 6, A and B
A silicone adhesive (manufactured by Toray Dow Corning Silicone Co., Ltd., SE9185) is applied to the organic semiconductor layer 3 by a screen printing method, cured at 50 ° C., and has a fluidity of silicone rubber having a width of 20 μm and a thickness of 3 μm. The electrode material repulsion region layers 6, A, and B were each formed.
[0158]
Step (3): Polystyrene sulfonic acid to which 0.01% by mass of a nonionic surfactant (for example, NP15 manufactured by Nikko Chemicals), which is a material for forming an electrode for forming a source electrode, a drain electrode, a pixel electrode, and a source bus line, is added. And an aqueous dispersion of poly (ethylenedioxythiophene) (Baytron P, manufactured by Bayer) was applied. When the coating film was divided by the fluid electrode material repulsion regions 6, A and B, the coating was dried at 60 ° C. A coating of the electrode forming material having a thickness of 0.2 μm was formed. Further, a silver paste is applied, and when the coating film is similarly divided by the fluid electrode repulsion regions 6, A and B, it is dried at 60 ° C. and heat-treated at 200 ° C. to obtain a 2 μm thick silver paste. A coating was formed.
[0159]
Through the above steps, the TFT sheet of the present invention is manufactured, and can be favorably driven.
[0160]
Example 2
<< Preparation of thin film transistor element sheet 2 >>
A thin film transistor element sheet 2 was manufactured in the same manner as in the manufacture of the thin film transistor 1 of Example 1, except that the following changes were made.
[0161]
(The formation of the organic semiconductor layer 3 is changed as follows)
A chloroform solution of a regular (poly (3-hexylthiophene)) body (manufactured by Aldrich) of poly (3-hexylthiophene) was prepared so as to have a Zn and Ni content of 10 ppm or less. This solution is discharged and patterned using a piezo type inkjet, dried at room temperature, and then dried.₂Heat treatment was performed at 50 ° C. for 30 minutes in a gas replacement atmosphere. At this time, the film thickness of poly (3-hexylthiophene) was 30 nm.
[0162]
Through the above steps, the TFT sheet of the present invention is manufactured, and can be favorably driven.
[0163]
Example 3
<< Preparation of thin film transistor element sheet 3 >>
A thin film transistor element sheet 3 was manufactured in the same manner as in Example 1 except that the following configuration was provided after the formation of the semiconductor layer.
[0164]
(Formation of intermediate layer): Provide PVA layer (thickness 0.3 μm)
On the organic semiconductor layer 3, a sufficiently purified polyvinyl alcohol is applied using an aqueous solution obtained by dissolving in water purified by an ultrapure manufacturing apparatus, and is thoroughly dried at 100 ° C. in a nitrogen gas atmosphere. An intermediate layer made of polyvinyl alcohol was formed.
[0165]
(Formation of Fluid Electrode Material Repulsion Area 6, A, B)
Further, a liquid obtained by diluting the following composition 2 with a single solvent of Isopar E ″ (isoparaffin hydrocarbon, manufactured by Exxon Chemical Co., Ltd.) on the intermediate layer is ejected as ink droplets by an inkjet method, and then dried and cured. As a result, fluid electrode material repulsion regions (layers) 6, A and B composed of a silicone rubber layer having a width of 7 μm and a thickness of 0.4 μm were formed.
[0166]
(Composition of composition 2)
α, ω-divinyl polydimethylsiloxane
(Molecular weight about 60,000) 100 parts
HMS-501 (methyl at both ends (methyl hydrogen siloxane)
(Dimethylsiloxane) copolymer, number of SiH groups / molecular weight =
0.69 mol / g, manufactured by Chisso Corporation 7 parts
Vinyl tris (methylethylketoximino) silane 3 parts
SRX-212 (platinum catalyst, manufactured by Dow Corning Toray Silicone Co., Ltd.)
5 copies
Further, the intermediate layer other than the area where the fluid electrode material repulsion areas 6, A and B were provided was removed by a water treatment or the like, and rinsed with ultrapure water.
[0167]
Thereafter, as in Example 1, the electrode material was supplied to form a two-layer electrode.
Through the above steps, the TFT sheet of the present invention is manufactured, and can be favorably driven.
[0168]
According to the production method of the present invention, as compared with the conventional production method of an element sheet, an element sheet having extremely high production efficiency (there is no short-circuit phenomenon between the source electrode and the drain electrode) and high transistor characteristics can be easily obtained. Was.
[0169]
In the method for manufacturing a thin film transistor element sheet of the present invention, a source electrode, a drain electrode, and the like formed in a channel region formed of an organic semiconductor layer may be formed only by patterning so as to straddle a fluid electrode material repulsion region. As shown in FIGS. 2A to 2C, the fluid electrode material ejected by the inkjet method is automatically divided on the fluid electrode material repulsion area and supplied to a predetermined area. One of the features is that a source electrode and a drain electrode are formed.
[0170]
As described above, even if the pattern accuracy for forming the electrode material is lower than that of the source electrode and drain electrode forming means which requires extremely high positional accuracy (pattern accuracy) as conventionally known, the electrode material repulsion region It can be understood that a thin film transistor can be formed if the condition of straddling is satisfied.
[0171]
As described above, in the method for manufacturing a thin film transistor of the present invention, the channel length of the TFT can be uniquely controlled by the width of the formed film, that is, the capacity and discharge amount (drawing density) of the ink-jet droplet, and the source electrode and the drain electrode It can be seen that a short circuit (also referred to as an SD electrode) can be effectively prevented, and a highly accurate and highly reliable TFT element can be stably manufactured by an extremely simple method.
[0172]
Further, a source electrode, a drain electrode, a pixel electrode, a source bus line, and the like can be formed by a simple method such as coating.
[0173]
【The invention's effect】
According to the present invention, it is possible to provide a method for easily and efficiently producing an organic thin film transistor element sheet with high accuracy without using a sophisticated vacuum system or complicated photolithography technology. In addition, it is possible to provide a method for producing an organic thin film transistor element sheet having high production stability by reducing the variation in element performance, and to provide a thin film transistor element sheet that does not require high-precision alignment that can be applied to a resin support such as a film. Could be provided.
[Brief description of the drawings]
FIG. 1 shows an example of a bottom gate type layer configuration of a thin film transistor element of the present invention.
FIG. 2 is a schematic diagram showing one embodiment of an organic thin film transistor forming one pixel of the thin film transistor element sheet of the present invention.
FIG. 3 is a schematic view illustrating one embodiment of a manufacturing process of a thin film transistor element of the present invention by an inkjet method.
FIG. 4 shows an example in which a fluid electrode material repulsion region is formed in a line shape.
FIG. 5 shows an example in which a fluid electrode material repulsion region is formed in a line shape.
FIG. 6 shows an example in which a fluid electrode material repulsion region is formed in a line shape.
FIG. 7 shows an example in which a fluid electrode material repulsion region is formed in a line shape.
FIG. 8 illustrates a method for manufacturing a thin film transistor element.
[Explanation of symbols]
1 Support
2 Gate electrode
2a Gate
3 Organic semiconductor layer
3a Intermediate layer
4 Drain electrode
4a Pixel electrode
5 Source electrode
6 Fluid electrode material repulsion area (layer)
7 Reception layer
8, 8a, 8b Ink droplets
10 Thin film transistor sheet
11 Gate bus line
12 Source bus line

Claims (12)

A thin film transistor element sheet in which a plurality of thin film transistor elements each having a gate electrode, a gate insulating layer, a channel region including a semiconductor layer, a source electrode and a drain electrode are connected to a support via a gate bus line and a source bus line. In the method for producing
Forming a flowable electrode material repelling region, directly or through another layer, on the channel region or on the support, and then the flowable electrode material is deposited on the channel region or on the support, A method for producing a thin film transistor element sheet, comprising a step of supplying at least the source electrode and the drain electrode supplied directly or through another layer. 2. The method according to claim 1, wherein the channel region intersects a gate bus line. 3. The method according to claim 1, wherein the support is a resin substrate. The fluid electrode material is supplied on a fluid electrode material repulsion area, and the fluid electrode material is divided on the repulsion area to form a source electrode and a drain electrode. 4. The method for producing a thin film transistor element sheet according to any one of the above items 3. The drain electrode forms a pixel electrode, or the drain electrode is connected to the pixel electrode, and the pixel electrode and the source bus line are separated by a fluid electrode material repulsion region. The method for producing a thin film transistor element sheet according to claim 1. The method for producing a thin film transistor element sheet according to claim 1, wherein the fluid electrode material is supplied by ink jet. The method for producing a thin film transistor element sheet according to claim 1, wherein, after the step of forming the fluid electrode material repulsion region, the fluid electrode material is supplied to the entire surface of the sheet. The method for manufacturing a thin film transistor element sheet according to claim 1, wherein the semiconductor layer contains an organic semiconductor material. The method for manufacturing a thin film transistor element sheet according to any one of claims 1 to 8, wherein the formation of the semiconductor layer is performed by inkjet. The method for producing a thin film transistor element sheet according to any one of claims 1 to 9, wherein the substrate is produced while transporting the support. The thin film transistor element sheet according to any one of claims 1 to 10, wherein a fluid electrode material repulsion region is formed in a line while transporting the support in a direction crossing the gate bus line. Production method. A thin film transistor element sheet manufactured by the manufacturing method according to claim 1.

Images