Reflective-transmission type thin film transistor liquid crystal display with non-oxidizing metal layer in first pixel electrode

• US 7,068,335 B2
• Filed: 01/22/2004
• Issued: 06/27/2006
• Est. Priority Date: 11/11/1999
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jang, Yong-Kyu, Joo, Young-Kuil, Kang, Myeon-Koo
• Primary Examiner(s): Schechter, Andrew
• Assistant Examiner(s): Wang, George Y.
• Application Number:
  US10/761,414
• Publication Number:
  US 20040207785A1
• Time in Patent Office: 887 Days
• Field of Search: 349/113, 349/114, 349/42, 349/43, 349/139
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

The present invention provide a reflective-transmission type TFT LCD wherein each of the reflective pixel electrode and the transmissive pixel electrode is connected directly to a source electrode of a thin film transistor, or the transmissive pixel electrode are concurrently formed with gate electrode and made with double layer of transparent conduction layer and metal layer which can be used as parameter conduction layer between the transparent conduction layer and the reflective pixel electrode. According to one aspect of the present invention, the reflective transmission type thin film transistor liquid crystal display (TFT LCD) comprises a glass substrate, at least one thin film transistor on the substrate for controlling a pixel, passivation layer having at least one contact hole in a source region of the thin film transistor, a transmissive pixel electrode which is formed on the passivation layer and is connected with a source electrode of the source region through a contact hole, a reflective pixel electrode which is formed on the passivation layer and is connected with the source electrode of the source region through a contact hole. And the pixel area is composed of a transparent area in which only the transmissive pixel electrode of whole pixel electrode exist and a reflective area in which the reflective pixel electrode exist.

Claims

1. A liquid crystal display (LCD) having a transmissive region and a reflective region, the LCD comprising:

a substrate;

a thin film transistor (TFT) formed on the substrate and comprising a gate electrode, a source electrode and a drain electrode;

a first pixel electrode formed on the same plane with the gate electrode, the first pixel electrode comprising;

a transparent conductive layer; and

a non-oxidizing metal layer formed on the transparent conductive layer and having a first opening corresponding to the transmissive region;

a passivation layer formed on the TFT and the first pixel electrode and having a contact hole exposing the source electrode and a second opening corresponding to the transmissive region; and

a second pixel electrode formed corresponding to the reflective region, on the passivation layer and connected to the non-oxidizing metal layer and e source electrode via the second opening and the contact hole, respectively, the second pixel electrode having a third opening corresponding to the transmissive region.

2. The LCD of claim 1, wherein the non-oxidizing metal layer is formed of Cr or MoW.

3. The LCD of claim 1, wherein the transparent conductive layer is formed of indium tin oxide (ITO) or indium zinc oxide (IZO).

4. The LCD of claim 1, wherein the passivation layer is formed of a photosensitive transparent insulating material.

5. The LCD of claim 4, wherein the passivation layer has embossment on a surface thereof.