Liquid crystal display having redundant pixel electrodes and thin film transistors and a manufacturing method thereof

• US 5,621,555 A
• Filed: 12/29/1994
• Issued: 04/15/1997
• Est. Priority Date: 12/31/1993
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Park, Jae D.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MILLER, CHARLES LELAND
• Application Number:
  US08/365,892
• Time in Patent Office: 838 Days
• Field of Search: 359/59, 359/87
• US Class Current: 349/54
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136245 having complementary transistors

Abstract

An improved liquid crystal display(LCD) and a manufacturing method thereof capable of advantageously reducing point defects caused due to the defects of the thin film transistor and of increasing an aperture ratio by providing an upper and lower structure of a pixel electrode, which includes a plurality of transparent conductive film used as a pixel electrode and being vertically formed; and at least one thin film transistor being electrically connected to each of transparent conductive films.

Claims

1. A liquid crystal display device, comprising:

a pair of transparent conductive films used as a pixel electrode and vertically formed; and

a first thin film transistor and a second thin film transistor electrically connected to respective one of said pair of transparent conductive films;

wherein said first thin film transistor is non-vertically electrically connected to its respective transparent conductive film and said second thin film transistor is vertically connected to its respective transparent conductive film through a contact hole.

2. The liquid crystal display of claim 1, wherein drain electrodes of the first thin film transistor and the second thin film transistor are electrically connected with each other.

3. A manufacturing method for a liquid crystal display, comprising the steps of:

a first step comprising depositing a gate electrode on a predetermined portion of a substrate;

a second step comprising depositing an insulating film on the upper surface of the gate electrode;

a third step comprising depositing a first transparent conductive film on a predetermined portion of the gate insulating film;

a fourth step comprising depositing an insulating film on the upper surface of the first transparent conductive film;

a fifth step comprising depositing a second transparency conductive film on a predetermined portion of the insulating film;

a sixth step comprising forming a contact hole for allowing a drain electrode of a first thin film transistor to be electrically connected to the first transparent conductive film; and

a seventh step comprising electrically connecting a drain electrode of the first thin film transistor to the first transparency conductive film and electrically connecting a drain electrode of a second thin film transistor to the second transparent conductive film.

4. The method of claim 3, including electrically connecting said drain electrodes of each thin film transistor to each other.

5. A liquid crystal display device having a two transistor structure, comprising:

a substrate;

a gate electrode formed on said substrate;

a first insulating layer formed on said gate electrode and said substrate;

a first transparent electrode formed on a portion of said first insulating layer;

a second insulating layer formed on said first insulating layer and said first transparent electrode;

a contact hole formed in said second insulating layer so as to expose a portion of said first transparent electrode;

a semiconductor layer formed on a portion of said second insulating layer;

a doped semiconductor layer formed on side portions of said semiconductor layer so as to expose a portion of said semiconductor layer therebetween;

a second transparent electrode formed on a portion of said second insulating layer;

a first transistor having a first source electrode and a first drain electrode formed on said doped semiconductor layer and said second insulating layer, said first drain electrode being electrically connected to said first transparent electrode through said contact hole; and

a second transistor having a second source electrode and a second drain electrode formed on said doped semiconductor layer and said second insulating layer, said second drain electrode being electrically connected to said second transparent electrode.

6. The liquid crystal display device of claim 5, wherein said first source electrode of said first transistor and said second source electrode of said second transistor are integrally formed.

7. The liquid crystal display device of claim 5, wherein said first and second drain electrodes are electrically connected with each other.

8. The liquid crystal display device of claim 7, wherein said first source electrode of said first transistor and said second source electrode of said second transistor are integrally formed.

9. A manufacturing method for a liquid crystal display device having a two transistor structure, comprising:

forming a gate electrode on a substrate;

forming a first insulating layer on said gate electrode and said substrate;

forming a first transparent electrode on a portion of said first insulating layer;

forming a second insulating layer on said first insulating layer and said first transparent electrode;

forming a contact hole at a portion of said second insulating layer so as to expose a portion of said first transparent electrode;

forming a semiconductor layer on a portion of said second insulating layer;

forming a dopant semiconductor layer on said semiconductor layer and removing a region of the same so as to expose a portion of said semiconductor layer;

forming a second transparent electrode on a portion of said second insulating layer; and

forming first and second source electrodes and first and second drain electrodes on said doped semiconductor layer and said second insulating layer, said first drain electrode being electrically connected to said first transparent electrode through said contract hole and said second drain electrode being electrically connected to said second transparent electrode.

10. The method of claim 9, wherein said first source electrode of said first transistor and said second source electrode of said second transistor are integrally formed.

11. The method of claim 9, wherein said first and second drain electrodes are electrically connected with each other.

12. The method of claim 11, wherein said first source electrode of said first transistor and said second source electrode of said second transistor are integrally formed.