Matrix array of active matrix LCD and manufacturing method thereof

• US 5,694,185 A
• Filed: 04/29/1996
• Issued: 12/02/1997
• Est. Priority Date: 11/25/1995
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Oh, Young-Jin
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGO, HUYEN LE
• Application Number:
  US08/639,617
• Time in Patent Office: 582 Days
• Field of Search: 349/42, 349/43, 349/44, 349/46
• US Class Current: 349/46
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

A matrix array of an active matrix liquid crystal display (AMLCD) and a manufacturing method thereof by which aperture ratio is enhanced by an optimum structure design of a line of the matrix array and a thin film transistor (TFT) so as to reduce power consumption, increase luminance, and lower reflection, thus improving contrast ratio. Aperture ratio is increased by forming the TFT above the gate line and providing non-linear TFT. The parasitic capacitor, occurring between the gate busline and the drain electrode, can be reduced when a TFT having the same channel length is manufactured due to effect of channel length extension. Therefore, level shifts of the pixel voltage can be reduced so that flicker is reduced and video quality is enhanced.

Claims

1. A matrix array of an active matrix liquid crystal display comprising:

an insulating substrate;

a gate line extending in a first direction on said substrate and having a first region corresponding to a gate electrode and a second region connected to and adjacent said first region, said first and second regions being separate portions of said gate line, and said gate line exposing a portion of said substrate;

a first insulating layer formed on said line and on said exposed portion of said substrate;

a first semiconductor layer formed above and in overlapping relation with said gate line;

a data line provided on said substrate and extending in a second direction crossing said second region of said gate line on said semiconductor layer and having a first protruding portion extending in said first direction above said first region of said gate line, and a second portion contiguous with said first portion, said second direction perpendicular to said first direction, said first and second portions being separate portions of said data line, and said first and second portions of said data line overlying said gate line;

a source electrode including said protruding portion of said data line;

a thin film transistor provided on said substrate including a drain electrode formed on the opposite side of said source electrode;

a pixel electrode coupled to said drain electrode and overlying said second region of said gate line; and

a storage capacitor including a portion of the second region of said gate line as a first storage capacitor electrode.

2. A matrix array of an active matrix liquid crystal display comprising according to claim 1, further comprising a substantially opaque layer partially lapping with said pixel electrode and provided above said gate line, said data line, said source electrode, and said drain electrode.

3. A matrix array of an active matrix liquid crystal display according to claim 1, further comprising a substantially opaque layer, wherein said substantially opaque layer overlaps a portion of said first storage capacitor electrode.

4. A matrix array of an active matrix liquid crystal display according to claim 3, wherein said storage capacitor comprises:

an electrode insulating layer formed on the exposed portion of said insulating substrate and said first storage capacitor electrode;

a second semiconductor layer formed on a portion of said electrode insulating layer, said second semiconductor layer being uncovered by said substantially opaque layer;

a second storage capacitor electrode formed on said second semiconductor layer; and

a passivation layer formed on said electrode insulating layer and said second storage capacitor electrode, wherein said substantially opaque layer has an exposed surface underlying said passivation layer to accommodate connection of said pixel electrode to said second storage capacitor electrode.

5. The matrix array of an active liquid crystal display according to claim 1, wherein said gate line is linear and has a substantially uniform width.

6. The matrix array of an active matrix liquid crystal display comprising according to claim 1, wherein said gate line has a protruding portion overlapping one side of said source electrode and partially overlapping said drain electrode.

7. The matrix array of an active matrix liquid crystal display comprising according to claim 1, wherein said source electrode and said drain electrode define a non-linear channel region of said thin film transistor.

8. The matrix array of an active matrix liquid crystal display according to claim 1, wherein said source electrode defines a non-linear channel region with said drain electrode above said gate line.

9. The matrix array of an active matrix liquid crystal display according to claim 1, wherein said semiconductor layer includes

an amorphous silicon layer;

and

a doped amorphous silicon layer.

10. A liquid crystal display comprising:

a gate line extending in a first direction;

a data line extending in a second direction different than said first direction, said second direction perpendicular to said first direction, and said data line having a protruding first portion extending in said first direction, and a second portion adjacent said first portion and extending in said second direction, wherein said first and second portions of said data line are contiguous and separate portions of said data line, and wherein said first and second portions overlying said gate line;

a source electrode including said first portion of said data line; and

a drain electrode spaced from said first and second portions of said data line and from said source electrode, wherein, upon application of a voltage to said gate line, a current flows from said first and second portions of said data line to said drain electrode.

11. A liquid crystal display device in accordance with claim 10, wherein said second portion of said data line is contiguous with said first portion of said data line.

12. A liquid crystal display device in accordance with claim 11, further comprising a substrate, wherein said gate line and data line are provided on said substrate, and said first and second portions of said data line define a region of said substrate, said source electrode overlying said region of said substrate.

13. A liquid crystal display device in accordance with claim 10, wherein said first and second directions are substantially perpendicular to each other.

14. A liquid crystal display device in accordance with claim 10, further comprising a substantially opaque layer overlying said first and second portions of said data line.

15. A liquid crystal display device in accordance with claim 14, further comprising:

a pixel electrode coupled to said drain electrode, a portion of said pixel electrode is formed on said substantially opaque layer.

16. A liquid crystal display device in accordance with claim 10, further comprising:

a substantially opaque layer overlying a first region of said gate line including a portion beneath said first and second portions of said data line, said substantially opaque layer exposing a second region of said gate line; and

a storage capacitor, said second region of said gate line serving as an electrode of said storage capacitor.

17. A liquid crystal display device in accordance with claim 16, further comprising a pixel electrode, a portion of which overlaps said second region of said gate line and serves as another electrode of said storage capacitor.

18. A liquid crystal display comprising:

a gate line having a first portion extending in a first direction and a second portion extending in a second direction different than said first direction;

a data line extending in said second direction, said data line having a protruding first portion extending in said first direction, and a second portion adjacent said first portion and extending in said second direction, said first portion of said data line overlying said first portion of said gate line, and said second portion of said data line overlying said second portion of said gate line;

a source electrode including said first portion of said data line; and

a drain electrode spaced from said first and second portions of said data line and from said source electrode, wherein, upon application of a voltage to said gate line, a current flows from said first and second portions of said data line to said drain electrode.

19. A liquid crystal display device in accordance with claim 18, wherein said first and second directions are substantially perpendicular to each other.

20. The liquid crystal display device in accordance with claim 18, wherein said first and second portions are contiguous and separate portions of said data line.

21. A liquid crystal display device in accordance with claim 18, further comprising a substrate, wherein said gate line and data line are provided on said substrate, and said first and second portions of said data line define a region of said substrate, said source electrode overlying said region of said substrate.

22. A method of fabricating a liquid crystal display device comprising the steps of:

providing a first conductive layer on a surface of a substrate;

patterning said first conductive layer on said surface of said substrate, said patterned first conductive layer exposing a portion of said surface of said substrate, and extending in a first direction on said surface of said substrate;

forming an insulative layer on said first conductive layer and said exposed portion of said surface of said substrate;

forming a semiconductor layer on said insulative layer, said semiconductor layer having an amorphous silicon layer and a doped amorphous silicon layer;

patterning said semiconductor layer to overlap said portion of said surface of said substrate and said first conductive layer;

forming a second conductive layer on said substrate; and

patterning said second conductive layer to form;

a data line over a portion of said semiconductor layer overlying said first conductive layer, and extending in a second direction different than said first direction, said data line having a protruding portion over said portion of said semiconductor layer overlying said first conductive layer and extending in said first direction; and

a source electrode overlying said exposed portion of said surface of said substrate, said source electrode being spaced from said protruding portion and a part of said data line contiguous with said protruding portion such that upon application of a voltage to said data line contiguous with protruding portion and from said protruding portion to said source electrode.

23. A method of fabricating a liquid crystal display device in accordance with claim 22, further comprising the steps of:

forming a transparent conductive layer overlying part of said exposed portion of said surface of said substrate; and

patterning said transparent conductive layer to form a pixel electrode in contact with said source electrode.

24. A method of fabricating a liquid crystal display device in accordance with claim 22, further comprising the step of:

forming a substantially opaque layer overlying said semiconductor layer.

25. A method of fabricating a liquid crystal display device in accordance with claim 22, wherein said first direction is substantially perpendicular to said second direction.

26. The method of fabricating a liquid crystal display device in accordance with claim 22, further including the step of

forming an oxide layer covering said patterned first conductive layer.