Active matrix display device

• US 8,558,453 B2
• Filed: 12/10/2008
• Issued: 10/15/2013
• Est. Priority Date: 02/18/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sakakura, Masayuki, Noda, Takeshi, Kuwabara, Hideaki, Yamazaki, Shunpei
• Primary Examiner(s): Hanley, Britt D
• Application Number:
  US12/331,679
• Publication Number:
  US 20090134399A1
• Time in Patent Office: 1,770 Days
• Field of Search: None
• US Class Current: 313/506
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/813 characterised by their shape
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/166 using selective deposition, e.g. using a mask

Abstract

A manufacturing method of an active matrix light emitting device in which the active matrix light emitting device can be manufactured in a shorter time with high yield at low cost compared with conventional ones will be provided. It is a feature of the present invention that a layered structure is employed for a metal electrode which is formed in contact with or is electrically connected to a semiconductor layer of each TFT arranged in a pixel area of an active matrix light emitting device. Further, the metal electrode is partially etched and used as a first electrode of a light emitting element. A buffer layer, a layer containing an organic compound, and a second electrode layer are stacked over the first electrode.

Claims

1. An active matrix display device comprising a plurality of pixels arranged in matrix, each pixel comprising:

a thin film transistor formed over a substrate, the thin film transistor comprising;

a semiconductor film comprising a metal oxide wherein the metal includes In;

a gate insulating film formed over the semiconductor film; and

a gate electrode formed over the semiconductor film with the gate insulating film interposed therebetween;

a first insulating film formed over the thin film transistor;

a first electrode formed over the first insulating film and electrically connected to the thin film transistor;

a second insulating film formed on a first portion of the first electrode wherein the second insulating film has an opening to expose a second portion of the first electrode;

a light emitting layer formed over the first electrode; and

a second electrode formed over the light emitting layer,

wherein the first electrode includes a first metal layer and a second metal layer formed on a portion of the first metal layer,

wherein the second metal layer is not formed in the second portion of the first electrode so that a side surface of the second metal layer closest to the second portion is covered by the second insulating film.

3. The active matrix display device according to claim 1 or 2 wherein the light emitting layer comprises an organic compound.

4. The active matrix display device according to claim 1 or 2 wherein the metal oxide of the semiconductor film further comprises gallium.

2. An active matrix display device comprising a plurality of pixels arranged in matrix, each pixel comprising:

a bottom gate thin film transistor formed over a substrate, the bottom gate thin file transistor comprising;

a semiconductor film comprising a metal oxide wherein the metal includes In;

a gate insulating film adjacent to the semiconductor film; and

a gate electrode adjacent to the semiconductor film with the gate insulating film interposed therebetween;

a first insulating film formed over the bottom gate thin film transistor;

a first electrode formed over the first insulating film and electrically connected to the bottom gate thin film transistor;

a second insulating film formed on a first portion of the first electrode wherein the second insulating film has an opening to expose a second portion of the first electrode;

a light emitting layer formed over the first electrode; and

a second electrode formed over the light emitting layer,

wherein the first electrode includes a first metal layer and a second metal layer formed on a portion of the first metal layer,

wherein the second metal layer is not formed in the second portion of the first electrode so that a side surface of the second metal layer closest to the second portion is covered by the second insulating film.