Active matrix type LCD having short resistors made of microcrystalline n+Si

• US 5,691,787 A
• Filed: 07/30/1996
• Issued: 11/25/1997
• Est. Priority Date: 08/25/1995
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shimada, Takayuki, Tanaka, Shinya, Miyamoto, Kazushige, Kondo, Naofumi
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): TON, MINH TOAN T
• Application Number:
  US08/681,965
• Time in Patent Office: 483 Days
• Field of Search: 349/40, 349/42, 349/140, 349/143, 257/59
• US Class Current: 349/40
• CPC Class Codes: G02F 1/136204 Arrangements to prevent high voltage or static electricity failures
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode

Abstract

The active matrix type liquid crystal display device of this invention, includes: a first substrate including a plurality of gate signal lines, a plurality of source signal lines crossing the plurality of gate signal lines, a switching element provided in the vicinity of each crossed point of the plurality of gate signal lines and the plurality of source signal lines, and a pixel electrode connected to the switching element; a second substrate having a counter electrode; and a liquid crystal layer interposed between the first and second substrates, wherein at least the plurality of gate signal lines are connected to each other by short resistors made of microcrystalline n+Si.

Claims

1. An active matrix type liquid crystal display device comprising:

a first substrate including a plurality of gate signal lines, a plurality of source signal lines crossing the plurality of gate signal lines, a switching element provided in the vicinity of each crossed point of the plurality of gate signal lines and the plurality of source signal lines, and a pixel electrode connected to the switching element;

a second substrate having a counter electrode; and

a liquid crystal layer interposed between the first and second substrates,

wherein at least the plurality of gate signal lines are connected to each other by short resistors made of microcrystalline n+Si.

2. An active matrix type liquid crystal display device according to claim 1, wherein the short resistors connect only the gate signal lines adjacent each other among the plurality of gate signal lines.

3. An active matrix type liquid crystal display device according to claim 1, wherein a resistance value of the short resistors is in the range between about 50 kΩ

and about 3 MΩ

.

4. An active matrix type liquid crystal display device according to claim 1, wherein the plurality of gate signal lines and the plurality of the source signal lines are connected to each other respectively by short resistors made of microcrystalline n+Si, and the short resistors connecting the plurality of source signal lines to each other have a resistance value of about 200 kΩ

or more.

5. An active matrix type liquid crystal display device according to claim 1, wherein the switching element includes a gate electrode, a gate insulating layer, a semiconductor layer, a source electrode and a drain electrode made of microcrystalline n+Si;

wherein each of the plurality of gate signal lines is connected to the gate electrode and is covered with the gate insulating layer, and each of the plurality of source signal lines is formed by a first conductive layer and is connected to the source electrode, and the pixel electrode is formed of a second conductive layer and is connected to the drain electrode; and

wherein input terminals of the plurality of gate signal lines are covered with the gate insulating layer having a contact hole, and a third conductive layer is formed so as to cover at least a part of the contact hole, and the short resistors are formed so as to be in contact with the third conductive layer formed at the gate input terminals adjacent each other.

6. An active matrix type liquid crystal display device according to claim 5, wherein the third conductive layer is made of material same as that forming at least one of the first conductive layer and the second conductive layer.

7. A method for fabricating an active matrix type liquid crystal display device including:

a plurality of gate signal lines;

a plurality of source signal lines crossing the plurality of gate signal lines;

a switching element provided in the vicinity of each crossed point of the plurality of gate signal lines and the plurality of source signal lines; and

a pixel electrode connected to the switching element, the method comprising the steps of;

forming the plurality of gate signal lines;

forming an insulating layer covering the plurality of gate signal lines;

forming contact holes at the insulating layer so that at least a part of input terminals of the plurality of gate signal lines are exposed;

forming short resistors made of microcrystalline n+Si on portions of the insulating layer so as to correspond to the intervals between the plurality of gate signal lines; and

forming a conductive layer covering at least a part of the contact holes and at least a part of the short resistors, so that the plurality of gate signal lines are electrically connected to each other via the short resistors.

8. A method for fabricating an active matrix liquid crystal display device according to claim 7, wherein the conductive layer is formed by a layer identical to a conductive layer forming at least either the pixel electrode or the plurality of source signal lines.