JPH0493928A - Liquid crystal display device - Google Patents

Liquid crystal display device

Info

Publication number
JPH0493928A
JPH0493928A JP2207909A JP20790990A JPH0493928A JP H0493928 A JPH0493928 A JP H0493928A JP 2207909 A JP2207909 A JP 2207909A JP 20790990 A JP20790990 A JP 20790990A JP H0493928 A JPH0493928 A JP H0493928A
Authority
JP
Japan
Prior art keywords
layer
insulating layer
film
liquid crystal
crystal display
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2207909A
Other languages
Japanese (ja)
Inventor
Hideto Kitakado
英人 北角
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ricoh Co Ltd
Original Assignee
Ricoh Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP2207909A priority Critical patent/JPH0493928A/en
Publication of JPH0493928A publication Critical patent/JPH0493928A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To eliminate the polarity difference of current-voltage characteristics and the flickering of display so as to improve image quality by forming a conductor layer in contact with the insulating layer of a nonlinear two-terminal element or the constituting layer thereof of the same material. CONSTITUTION:The film of ITO is formed by a method, such as sputtering, on a glass substrate 1 and is wet etched by an etchant of ferric chloride type, by which picture element electrodes 2 are formed. The film of SiO2, Al2O3, etc., to constitute the insulating layer 3 is formed by a method, such as sputtering or CVD method., Finally, an ITO film and an In-Sn film are respectively formed as electrodes 4 for the two-terminal element and scanning electrodes 5. The formation of the ITO film is executed in a reactive sputtering or ion plating device in oxygen plasma, by which the continuous formation of the two films within the same chamber is allowed. Since the two layers 2, 4 holding the insulating layer 3 there between are formed of the same material, the polarity difference of the current-voltage characteristics of the MIM element is eliminated.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は非線形2端子素子を使ったアクティブマトリッ
クス型液晶表示装置に関するものである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an active matrix liquid crystal display device using nonlinear two-terminal elements.

〔従来の技術〕[Conventional technology]

液晶表示装置の代表的な駆動方式の1つにアクティブマ
トリックス駆動方式があり、この方式は、走査電極数を
数百本も必要とするビデオ表示や、CRT表示に匹敵す
る大容量表示が可能という点で着目されており、特に液
晶プリンターヘッド等、高速応答、高コントラストを要
する空間変調素子及び高デユーティ駆動を必要とする液
晶表示装置への応用が期待されている。このアクティブ
マトリックス能動方式を用いた液晶表示装置は、各画素
ごとにスイッチング素子を付加する構成となっており、
このスイッチング素子として、金属−絶縁膜−金属から
構成されたMIM素子あるいは金属−セミインシュレー
ター−金属から構成されたMSI素子が種々の文献に発
表されている。
One of the typical driving methods for liquid crystal display devices is the active matrix driving method, which is said to be capable of video displays that require hundreds of scanning electrodes and large-capacity displays comparable to CRT displays. It is expected to be applied to spatial modulation elements that require high-speed response and high contrast, such as liquid crystal printer heads, and liquid crystal display devices that require high duty driving. A liquid crystal display device using this active matrix active method has a configuration in which a switching element is added to each pixel.
As this switching element, an MIM element composed of metal-insulating film-metal or an MSI element composed of metal-semi-insulator-metal has been published in various documents.

第3図にアクティブマトリックス型液晶表示装置に使用
される従来のスイッチング用非線形2端子素子(HIM
素子)の構造例を示す。ガラス基板11上にTaからな
る走査電極12及びTa01からなる1811層13が
順に形成され、この絶縁層13の一部と、同じくガラス
基板11上に設けられたITOからなる画素電極15の
一部とにまたがるようにCrからなる上部電極14が形
成され、走査電極】2.絶縁層13及び上部電極14に
よりTa/TaOx/CrからなるHIM素子が構成さ
れている。
Figure 3 shows a conventional switching nonlinear two-terminal element (HIM) used in active matrix liquid crystal display devices.
An example of the structure of an element) is shown below. A scanning electrode 12 made of Ta and an 1811 layer 13 made of Ta01 are sequentially formed on a glass substrate 11, and part of this insulating layer 13 and a part of a pixel electrode 15 made of ITO also provided on the glass substrate 11. An upper electrode 14 made of Cr is formed so as to span the scanning electrode]2. The insulating layer 13 and the upper electrode 14 constitute a HIM element made of Ta/TaOx/Cr.

一方、第4図は同じくスイッチング用非線形2端子素子
として使用される従来のMSI素子の構造例を示す図で
、ガラス基板11上に設けられたITOからなる画素電
極15の一部にかかるように5iNzからなるセミイン
シュレーター層16とCrからなる走査電極17が順に
形成され、これらによってITO/SiNx/Crから
なるMSI素子が構成されている。
On the other hand, FIG. 4 is a diagram showing an example of the structure of a conventional MSI element used as a nonlinear two-terminal element for switching. A semi-insulator layer 16 made of 5iNz and a scanning electrode 17 made of Cr are formed in this order, and these constitute an MSI element made of ITO/SiNx/Cr.

上述したいずれの2端子素子も薄膜トランジスター素子
に比べて素子の構造及び製造プロセスが簡単で大面積化
、低コスト化に有利である。
Any of the two-terminal devices described above has a simpler device structure and manufacturing process than a thin film transistor device, and is advantageous in terms of larger area and lower cost.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

しかしながら、第3図に示す従来のMIN素子では、絶
縁層13がTaOxからなる為、上部電極14に走査電
極12と同じTaを用いた場合、上部電極14のパター
ニング時に絶縁層13もエツチングされ、MIM素子の
寸法精度がばらつくという問題がある。また第4図の例
では、MSI素子の2導体層の片方をITO等の画素電
極15としている為、走査電極17にも同一材料を使用
することはできない、なぜならばITOの比抵抗は10
−4Ω・cmオーダーである為、電圧降下がないように
するには金属電極の数十倍の膜厚が必要となる。これら
の理由のため従来、MIM素子の絶縁層あるいはMSI
素子のセミインシュレーター層を挾む2導体層をそれぞ
れ異なる材質により形成していた。ところが、この2導
体層を異なる材質で形成すると、電流−電圧特性の極性
差が生じてしまい、これが液晶表示装置の表示品質を劣
化させるという問題があった。
However, in the conventional MIN device shown in FIG. 3, the insulating layer 13 is made of TaOx, so if the same Ta as the scanning electrode 12 is used for the upper electrode 14, the insulating layer 13 will also be etched during patterning of the upper electrode 14. There is a problem that the dimensional accuracy of the MIM element varies. Furthermore, in the example shown in FIG. 4, since one of the two conductor layers of the MSI element is used as the pixel electrode 15 made of ITO or the like, the same material cannot be used for the scanning electrode 17, because the specific resistance of ITO is 10.
Since it is on the order of -4 Ω·cm, the film needs to be several tens of times thicker than the metal electrode in order to avoid voltage drop. For these reasons, conventionally, the insulating layer of MIM device or MSI
The two conductor layers sandwiching the semi-insulator layer of the device were made of different materials. However, when the two conductor layers are formed of different materials, a polarity difference occurs in current-voltage characteristics, which causes a problem in that the display quality of the liquid crystal display device deteriorates.

本発明はこのような従来技術の問題を解決し、液晶表示
装置における電流−電圧特性の極性差をなくし、表示品
質の優れた液晶表示装置を提供することを目的とする。
SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, eliminate the polarity difference in current-voltage characteristics in a liquid crystal display, and provide a liquid crystal display with excellent display quality.

〔課題を解決するための手段〕[Means to solve the problem]

上記目的を達成するため、本発明によれば、複数の行電
極が形成された基板と、複数の列電極が形成された基板
が液晶層を挟んで対向し、少なくとも一方の基板には絶
縁層とこれを挟む2導体層とからなる線形素子が設けら
れているアクティブマトリックス型液晶表示装置におい
て、非線形素子の2導体層の少なくとも一方が金属層及
びその金属酸化物層の2層がらなり、がっ、絶縁層と接
する導体層もしくはその構成層がともに同一材料により
形成されていることを特徴とする液晶表示装置が提供さ
れる。
To achieve the above object, according to the present invention, a substrate on which a plurality of row electrodes are formed and a substrate on which a plurality of column electrodes are formed are opposed to each other with a liquid crystal layer in between, and at least one of the substrates has an insulating layer. In an active matrix liquid crystal display device in which a linear element is provided, at least one of the two conductor layers of the non-linear element is composed of a metal layer and its metal oxide layer, and First, there is provided a liquid crystal display device characterized in that the conductor layer in contact with the insulating layer or its constituent layers are both formed of the same material.

〔作用〕[Effect]

本発明では、液晶表示装置における線形素子の絶縁層に
接する導体層あるいはその構成層とその反対側に設けら
れた導体層あるいはその構成層とを同一材料で形成した
ことにより、電流−電圧特性の極性差がなくなり、また
絶縁層を挾む2導体層の少なくとも一方を金属層とその
金属酸化物層の2層構造としたことにより上記のように
M!縁層に接する層の材料を同じにしても前述のような
不都合は生じない。したがって、前記従来技術の課題が
解決される。
In the present invention, the conductor layer or its constituent layers in contact with the insulating layer of the linear element in the liquid crystal display device and the conductor layer or its constituent layers provided on the opposite side are formed of the same material, thereby improving current-voltage characteristics. There is no polarity difference, and because at least one of the two conductor layers sandwiching the insulating layer has a two-layer structure of a metal layer and its metal oxide layer, M! Even if the material of the layer in contact with the edge layer is the same, the above-mentioned disadvantage does not occur. Therefore, the problems of the prior art described above are solved.

〔実施例〕〔Example〕

以下本発明を実施例により詳細に説明する。 The present invention will be explained in detail below with reference to Examples.

第1図は本発明の一実施例の液晶表示装置に用いられる
二端子素子(MIM素子)の構造を示す図である。この
MIN素子は、ガラス基板1上に設けられたITOから
なる画素電極2と、この上に形成された5in2、A 
120.等からなる絶縁層3と、ITOからなる二端子
素子用電極4と、In−5nからなる走査電極5により
構成されている。すなわち、絶縁層3を挟む2導体層の
一方が、金属層(In−5n)とその金属酸化物層(I
TO)との2層構造をなし、絶縁層3に接する画素電極
2と二端子素子用電極4がともに同一材料(ITO)で
形成されている。
FIG. 1 is a diagram showing the structure of a two-terminal element (MIM element) used in a liquid crystal display device according to an embodiment of the present invention. This MIN element includes a pixel electrode 2 made of ITO provided on a glass substrate 1, and a 5in2, A
120. The two-terminal element electrode 4 is made of ITO, and the scanning electrode 5 is made of In-5n. That is, one of the two conductor layers sandwiching the insulating layer 3 is a metal layer (In-5n) and its metal oxide layer (I
The pixel electrode 2 and the two-terminal element electrode 4 which are in contact with the insulating layer 3 are both made of the same material (ITO).

次に、このMIM素子の作成方法について述べると、ま
ずガラス基板l上に、ITOをスパッタリング等の方法
により成膜し、たとえば塩化第二鉄型のエッチャントに
よりウェットエツチングすることによって画素電極2を
形成する。次に絶縁層3となるSin、、Al2O,等
の膜をスパッタリング、CVD法等の方法により形成す
る。最後に二端子素子用電極4及び走査電極5としてそ
れぞれI丁0膜及びIn−5n膜を成膜する。ここで、
ITO成膜を、酸素プラズマ中の反応性スパッタリング
またはイオンブレーティング装置で行うことにより両膜
の成膜を連続して同一チャンバー内で行うことが可能と
なる。以上のようにして本発明のHIM素子が作成され
る。
Next, to describe the method for manufacturing this MIM element, first, ITO is formed into a film on a glass substrate l by a method such as sputtering, and then the pixel electrode 2 is formed by wet etching with, for example, a ferric chloride type etchant. do. Next, a film of Sin, Al2O, etc., which will become the insulating layer 3, is formed by a method such as sputtering or CVD. Finally, an I-0 film and an In-5n film are formed as the two-terminal element electrode 4 and the scanning electrode 5, respectively. here,
By performing ITO film formation using reactive sputtering in oxygen plasma or using an ion blating device, it becomes possible to form both films continuously in the same chamber. The HIM element of the present invention is produced in the manner described above.

なお、−作成例における各層の膜厚を例示すると、Al
2O,/ITO/In−5n=500/1000/30
00(人)であった。
In addition, to illustrate the film thickness of each layer in the - creation example, Al
2O,/ITO/In-5n=500/1000/30
There were 00 (people).

上記のような構成によれば、絶縁層3を挟む両層2.4
が同一材料で形成されているため、MIM素子の電流−
電圧特性の極性差がなくなり、2層構造をなす導体層4
,5のうちの一方をIn−5n膜(走査電極)で形成し
ているため、パターニングの際に不用意に絶縁層3がエ
ツチングされることがなく、また電圧降下が防止される
。従って、表示のちらつきがなくなる等画質が向上する
。その上、この2層構造をなす導体層4.5は金属とそ
の金属酸化物よりなるため、これらの層は、反応性スパ
ッタ装置またはイオンブレーティング装置を使って連続
的に同一チャンバー内で成膜できるので、スループット
を向上させることができる。
According to the above configuration, both layers 2.4 sandwiching the insulating layer 3
are made of the same material, the current of the MIM element -
The conductor layer 4 has a two-layer structure with no polarity difference in voltage characteristics.
, 5 is formed of an In-5n film (scanning electrode), the insulating layer 3 is not inadvertently etched during patterning, and a voltage drop is prevented. Therefore, the image quality is improved, such as eliminating display flickering. Moreover, since this two-layer conductor layer 4.5 is composed of a metal and its metal oxide, these layers can be formed successively in the same chamber using a reactive sputtering device or an ion-blating device. Since a membrane can be formed, throughput can be improved.

次に、本発明の別の実施例を第2図に示す。この実施例
のMIに素子は、ガラス基板1上に設けられたITOか
らなる画素電極2と、その上に形成されたIn−5nか
らなる二端子素子用電極6と5102、Al2O。
Next, another embodiment of the present invention is shown in FIG. The MI element of this example includes a pixel electrode 2 made of ITO provided on a glass substrate 1, two-terminal element electrodes 6 and 5102 made of In-5n formed thereon, and Al2O.

等からなる絶縁層3と、In−5nからなる走査電極5
により構成されている。この場合も、前述の実施例と同
様に、絶縁層3を挟む2導体層の一方が、金属層(In
−5n)とその金属酸化物層(ITO)との2層構造を
なし、絶縁層3に接する二端子素子用電極6と走査電極
5がともに同一材料(In−3n)で形成されている。
an insulating layer 3 made of In-5n, and a scanning electrode 5 made of In-5n.
It is made up of. In this case as well, one of the two conductor layers sandwiching the insulating layer 3 is a metal layer (In
-5n) and its metal oxide layer (ITO), and both the two-terminal element electrode 6 and the scanning electrode 5 in contact with the insulating layer 3 are formed of the same material (In-3n).

このHIM素子も前述の実施例のMIM素子と同様な方
法を用いて作成することができる。すなわち、ガラス基
板1上にITO膜、In−5nを順次形成し、2回のフ
ォトリソグラフィーによって画素電極2と二端子素子用
電極6をパターニングする。In−5n合金層はMIN
素子形成部にのみ残し、画素部はエツチングにより除去
する。次いで5in2、A1□0□等からなる絶縁層3
を成膜した後、その上にIn−5n合金膜を成膜し、エ
ツチングにより工n−5n合金膜をパタニングし、走査
電極5を形成する。なお、にIM素子形成部以外の絶縁
層は不要であるが、必ずしも除去する必要はない。
This HIM element can also be produced using the same method as the MIM element of the above-described embodiment. That is, an ITO film and an In-5n film are sequentially formed on a glass substrate 1, and the pixel electrode 2 and the two-terminal element electrode 6 are patterned by photolithography twice. In-5n alloy layer is MIN
It is left only in the element forming area, and the pixel area is removed by etching. Next, an insulating layer 3 made of 5in2, A1□0□, etc.
After forming a film, an In-5n alloy film is formed thereon, and the In-5n alloy film is patterned by etching to form the scanning electrode 5. Note that the insulating layer other than the IM element forming portion is unnecessary, but does not necessarily need to be removed.

このような構造のMIM素子においても、前述と同様な
作用効果を得ることができる。
Even in the MIM element having such a structure, the same effects as described above can be obtained.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、非線形二端子素子を設けたアクティブ
マトリックス型液晶表示装置において非線形二端子素子
の絶縁層に接する導体層もしくはその構成層を同一材料
により形成することによって電流−電圧特性の極性差を
なくすことができ、表示のつらっきが無くなる等画質の
向上が達成できる。
According to the present invention, in an active matrix type liquid crystal display device provided with a nonlinear two-terminal element, the conductor layer or its constituent layers in contact with the insulating layer of the nonlinear two-terminal element are formed of the same material, so that the polarity difference in current-voltage characteristics is Therefore, it is possible to improve image quality by eliminating display stutter.

また、非線形二端子素子の絶縁層を挾む二導体層の少な
くとも一方を金属層とその金属酸化物層との2層構造と
したので、他層の不用意なエツチングが避けられ寸法精
度が向上し、また電圧降下が防止される。しかも、これ
らの層は反応性スパッタ装置又はイオンブレーティング
装置を使って連続的に同一チャンバー内で成膜できるた
め、スループットが向上する。
In addition, since at least one of the two conductor layers sandwiching the insulating layer of the nonlinear two-terminal element has a two-layer structure consisting of a metal layer and its metal oxide layer, careless etching of other layers is avoided and dimensional accuracy is improved. In addition, voltage drop is prevented. Furthermore, these layers can be successively deposited in the same chamber using a reactive sputtering device or an ion blating device, thereby improving throughput.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図及び第2図はそれぞれ本発明による液晶表示装置
におけるHIM素子の構成例を示す断面図、第3図及び
第4図はそれぞれ従来のMIM素子及びMSI素子の構
成例を示す断面図である。 1・・・ガラス基板 2・・・画素電極 3・・・絶縁層 4.6・・・二端子素子用電極 5・・・走査電極 特許出願人 株式会社 リ  コ
1 and 2 are cross-sectional views showing examples of the configuration of a HIM element in a liquid crystal display device according to the present invention, and FIGS. 3 and 4 are cross-sectional views showing examples of the configuration of a conventional MIM element and an MSI element, respectively. be. 1...Glass substrate 2...Pixel electrode 3...Insulating layer 4.6...Two-terminal element electrode 5...Scanning electrode patent applicant Rico Co., Ltd.

Claims (1)

【特許請求の範囲】[Claims] (1)複数の行電極が形成された基板と、複数の列電極
が形成された基板が液晶層を挟んで対向し、少なくとも
一方の基板には絶縁層とこれを挟む2導体層とからなる
線形素子が設けられているアクティブマトリックス型液
晶表示装置において、非線形素子の2導体層の少なくと
も一方が金属層及びその金属酸化物層の2層からなり、
かつ、絶縁層と接する導体層もしくはその構成層がとも
に同一材料により形成されていることを特徴とする液晶
表示装置。
(1) A substrate on which a plurality of row electrodes are formed and a substrate on which a plurality of column electrodes are formed face each other with a liquid crystal layer in between, and at least one substrate has an insulating layer and two conductor layers sandwiching it. In an active matrix liquid crystal display device provided with a linear element, at least one of the two conductor layers of the nonlinear element is composed of a metal layer and a metal oxide layer thereof,
A liquid crystal display device characterized in that the conductor layer in contact with the insulating layer or its constituent layers are both formed of the same material.
JP2207909A 1990-08-06 1990-08-06 Liquid crystal display device Pending JPH0493928A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2207909A JPH0493928A (en) 1990-08-06 1990-08-06 Liquid crystal display device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2207909A JPH0493928A (en) 1990-08-06 1990-08-06 Liquid crystal display device

Publications (1)

Publication Number Publication Date
JPH0493928A true JPH0493928A (en) 1992-03-26

Family

ID=16547578

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2207909A Pending JPH0493928A (en) 1990-08-06 1990-08-06 Liquid crystal display device

Country Status (1)

Country Link
JP (1) JPH0493928A (en)

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