Thin film transistor and organic light emitting diode display including the same

Patent metadata

Field	Value
Publication number	US-2016155858-A1
Application number	US-201514718336-A
Country	US
Kind code	A1
Filing date	May 21, 2015
Priority date	Nov 28, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

A thin film transistor including a substrate; a first gate electrode on the substrate; a first insulating layer covering the substrate and the first gate electrode; a semiconductor on the first insulating layer and overlapping the first gate electrode; a second insulating layer covering the first insulating layer and the semiconductor; a second gate electrode on the second insulating layer and crossing the first gate electrode in plane; a third insulating layer covering the second gate electrode and the second insulating layer; a first source electrode and a first drain electrode on the third insulating layer and connected to the semiconductor; and a second source electrode and a second drain electrode on a same layer as the first source electrode and the first drain electrode and connected to the semiconductor.

First claim

What is claimed is:

1 . A thin film transistor, comprising:
a substrate; a first gate electrode on the substrate; a first insulating layer covering the substrate and the first gate electrode; a semiconductor on the first insulating layer and overlapping the first gate electrode; a second insulating layer covering the first insulating layer and the semiconductor; a second gate electrode on the second insulating layer and crossing the first gate electrode in plane; a third insulating layer covering the second gate electrode and the second insulating layer; a first source electrode and a first drain electrode on the third insulating layer and connected to the semiconductor; and a second source electrode and a second drain electrode on a same layer as the first source electrode and the first drain electrode and connected to the semiconductor.

2 . The thin film transistor as claimed in claim 1 , wherein:
the first source electrode and the first drain electrode are positioned in a length direction of the first gate electrode, and the second source electrode and the second drain electrode are positioned in a length direction of the second gate electrode.

3 . The thin film transistor as claimed in claim 2 , wherein:
the first source electrode and the first drain electrode face each other based on the second gate electrode, and the second source electrode and the second drain electrode face each other based on the first gate electrode.

4 . The thin film transistor as claimed in claim 3 , wherein the semiconductor includes:
a first channel region overlapping the second gate electrode, and a first source region and a first drain region positioned at respective sides of the first channel region, and a second channel region overlapping the first gate electrode, and a second source region and a second drain region positioned at respective sides of the second channel region, and the first channel region and the second channel region correspond to a same region.

5 . The thin film transistor as claimed in claim 4 , wherein:
the first source electrode and the first drain electrode are connected to the first source region and the first drain region through a pair of first contact holes which are formed in the second insulating layer and the third insulating layer to expose the first source region and the first drain region, respectively, and the second source electrode and the second drain electrode are connected to the second source region and the second drain region through a pair of second contact holes which are formed in the second insulating layer and the third insulating layer to expose the second source region and the second drain region, respectively.

6 . The thin film transistor as claimed in claim 4 , wherein the first source electrode, the second source electrode, the first drain electrode, and the second drain electrode surround the first channel region in plane.

7 . The thin film transistor as claimed in claim 1 , further comprising:
a first gate line transferring a first gate signal to the first gate electrode; and a second gate line transferring a second gate signal to the second gate electrode, wherein: the first gate electrode is a part of the first gate line, the second gate electrode is a part of the second gate line, and the first gate line and the second gate line are electrically separated from each other.

8 . An organic light emitting diode display, comprising:
a substrate; a thin film transistor on the substrate; and an organic light emitting diode connected to the thin film transistor, the thin film transistor including: a first gate electrode on the substrate, a first insulating layer covering the substrate and the first gate electrode, a semiconductor on the first insulating layer and overlapping the first gate electrode, a second insulating layer covering the first insulating layer and the semiconductor, a second gate electrode on the second insulating layer and crossing the first gate electrode in plane, a third insulating layer covering the second gate electrode and the second insulating layer, a first source electrode and a first drain electrode on the third insulating layer and connected to the semiconductor, and a second source electrode and a second drain electrode on a same layer as the first source electrode and the first drain electrode and connected to the semiconductor.

9 . The organic light emitting diode display as claimed in claim 8 , wherein:
the first source electrode and the first drain electrode are positioned in a length direction of the first gate electrode, and the second source electrode and the second drain electrode are positioned in a length direction of the second gate electrode.

10 . The organic light emitting diode display as claimed in claim 9 , wherein:
the first source electrode and the first drain electrode face each other based on the second gate electrode, and the second source electrode and the second drain electrode face each other based on the first gate electrode.

11 . The organic light emitting diode display as claimed in claim 10 , wherein the semiconductor includes:
a first channel region overlapping the second gate electrode, and a first source region and a first drain region positioned at respective sides of the first channel region, and a second channel region overlapping the first gate electrode, and a second source region and a second drain region positioned at respective sides of the second channel region, and the first channel region and the second channel region correspond to a same region.

12 . The organic light emitting diode display as claimed in claim 11 , wherein the first source electrode, the second source electrode, the first drain electrode, and the second drain electrode surround the first channel region in plane.

Assignees

• Samsung Display Co Ltd

Inventors

• Yoo Hee Jun
• Park Sang Ho
• Park Joung-Keun
• Ahn Ki Wan
• Yoon Joo Sun
• Lee Seung Min
• Jang Yong Jae
• Jang Jae Hyuk
• Choi Kwang Young
• Kim Jung Hyun

Classifications

• H10D30/6733 Primary

  Multi-gate TFTs · CPC title

• H10D84/401

  Combinations of FETs or IGBTs with BJTs · CPC title

• H10D30/6757

  characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715) · CPC title

• H10D30/6745

  Polycrystalline or microcrystalline silicon · CPC title

• H10D30/6729

  characterised by the electrodes · CPC title