Transflective liquid crystal display device and method of fabricating the same

• US 8,368,856 B2
• Filed: 05/23/2011
• Issued: 02/05/2013
• Est. Priority Date: 09/09/2005
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Jung Il, Yang, Joong-Young
• Primary Examiner(s): Rude, Timothy L
• Application Number:
  US13/114,033
• Publication Number:
  US 20110220902A1
• Time in Patent Office: 624 Days
• Field of Search: 349/114
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2203/02 reflective

Abstract

An array substrate for a transflective liquid crystal display device includes: a substrate; a gate line and a data line on the substrate, the gate line and the data line crossing each other to define a pixel region including a transmissive area and a reflective area surrounding the transmissive area; a thin film transistor having a gate insulating layer, the thin film transistor electrically connected to the gate line and the data line; a first passivation layer having a drain contact hole exposing a drain electrode of the thin film transistor and a through hole exposing the substrate in the transmissive area; a pixel electrode on the first passivation layer, the pixel electrode contacting the substrate in the transmissive area through the through hole; and a reflective plate on the pixel electrode, the reflective plate being electrically connected to the drain electrode through the drain contact hole and to the pixel electrode.

Claims

1. A method of fabricating an array substrate for a transflective liquid crystal display device, comprising:

forming a gate line and a data line on a substrate, the gate line and the data line crossing each other to define a pixel region including a transmissive area and a reflective area surrounding the transmissive area;

forming a gate insulating layer between the gate line and the data line;

forming a thin film transistor connected to the gate line and the data line;

forming a first passivation layer on the thin film transistor, the first passivation layer having a drain contact hole exposing a drain electrode of the thin film transistor and a through hole exposing the gate insulating layer on the substrate in the transmissive area;

forming a second passivation layer on the first passivation layer;

forming a first photoresist pattern on the second passivation layer, the first photoresist pattern exposing the drain contact hole and the through hole;

etching the second passivation layer and the gate insulating layer using the first photoresist pattern as an etch mask such that the drain electrode is exposed through the drain contact hole and the substrate is exposed through the through hole;

forming a transparent conductive material layer on the first photoresist pattern and on the second passivation layer;

changing the crystalline state of the transparent conductive material layer such that the crystalline state of first portions of the transparent conductive material layer on the first passivation layer are different than second portions of the transparent conductive material layer over the first passivation layer;

forming a first photoresist layer on the transparent conductive material layer;

anisotropically removing the first photoresist layer to form a second photoresist pattern on the transparent conductive material layer in the drain contact hole and the through hole;

selectively etching the second portions of the transparent conductive material layer to form a drain terminal in the drain contact hole and a pixel electrode in the through hole;

removing the first and second photoresist patterns; and

forming a reflective plate on the drain terminal and the pixel electrode, the reflective plate contacting the drain terminal and the pixel electrode.

2. The method according to claim 1, wherein changing the crystalline state includes one of a laser process or ultraviolet treatment after forming the transparent conductive layer.