Transreflection-type liquid crystal display device and method of fabricating the same

• US 7,161,648 B2
• Filed: 12/30/2003
• Issued: 01/09/2007
• Est. Priority Date: 04/15/2003
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Lim, Byoung Ho, Nam, Chul, Park, Jong Woo, Kim, Gyu Bong, Kim, Seong Hee
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): NGUYEN, THANH NHAN P
• Application Number:
  US10/747,073
• Publication Number:
  US 20040207784A1
• Time in Patent Office: 1,106 Days
• Field of Search: 349/39, 349/113, 349/114, 349/138
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps

Abstract

A transreflection-type liquid crystal display (LCD) device includes a plurality of gate and data lines on a substrate crossing each other defining a plurality of pixel regions, a plurality of storage lines parallel to the gate lines, each storage line positioned between the gate lines, a plurality of thin film transistors disposed at the crossings of the gate and data lines, each thin film transistor having source and drain electrodes and a U-shaped channel region, a negative-type organic insulating layer within the pixel region except for a transmission part, the negative type organic insulating layer having at least one of concave and convex patterns thereon, a reflective electrode on the negative-type organic insulating layer within the pixel region except for the transmission part, and a transparent electrode within the pixel region in electrical contact with the drain electrode.

Claims

1. A method for fabricating a transreflection-type liquid crystal display (LCD) device, comprising:

forming a gate line and a storage line on a substrate using a first mask;

forming a gate insulating layer on the substrate;

forming a data line and a thin film transistor having source and drain electrodes using a second mask by depositing a semiconductor layer and a metal layer on the substrate including the gate line and the storage line, the data line being perpendicular to the gate line to define a pixel region;

forming a negative-type organic insulating layer having at least one of concave and convex patterns therein using a third mask, the concave and convex patterns formed within the pixel region except for a transmission part;

forming a reflective electrode on the negative-type organic insulating layer formed within the pixel region except for the transmission part, using a fourth mask;

forming a contact hole on a drain electrode using a fifth mask; and

forming a transparent electrode within the pixel region using a sixth mask to be connected with the drain electrode through the contact hole.

2. The method according to claim 1, wherein the thin film transistor includes a U-shaped channel region.

3. The method according to claim 1, further comprising:

forming a gate pad at one end portion of the gate line during forming of the gate line;

forming a data pad at one end portion of the data line during forming of the data line;

forming a contact hole in each of the gate pad and the data pad during forming of the contact hole in the drain electrode; and

forming a pad terminal in each of the gate pad and the data pad using a same material as the transparent electrode during forming of the transparent electrode.

4. The method according to claim 1, wherein the forming of the data line and the thin film transistor includes:

depositing a photo-resist layer on the metal layer;

patterning the photo-resist layer during a diffraction exposure using a second mask to reduce a thickness portion of the photo-resist layer corresponding to the channel region of the thin film transistor;

etching the semiconductor layer and the metal layer by using the patterned photo-resist layer as a mask;

ashing the photo-resist layer to remove the portion corresponding to the channel region; and

etching the metal layer using the photo-resist layer as a mask.

5. The method according to claim 1, wherein the negative-type organic insulating layer includes a negative-type photoacryl.

6. The method according to claim 1, wherein the concave and convex patterns of the negative-type organic insulating layer are using a stamping process.

7. The method according to claim 1, further comprising hardening the negative-type organic insulating layer using UV light.

8. The method according to claim 1, further comprising re-curing the negative-type organic insulating layer.

9. The method according to claim 8, wherein the re-curing process is performed at a temperature between about 160°

C. and about 240°

C. during a period of about 40 to about 80 minutes.

10. The method according to claim 1, further comprising forming a passivation layer between the reflective electrode and the transparent electrode.

11. The method according to claim 10, wherein the passivation layer includes one of SiO_x and SiN_x.

12. The method according to claim 10, wherein the passivation layer is formed at a temperature between about 180°

C. and about 220°

C.