Display backplane having multiple types of thin-film-transistors

Patent metadata

Field	Value
Publication number	US-9634038-B2
Application number	US-201414588205-A
Country	US
Kind code	B2
Filing date	Dec 31, 2014
Priority date	Feb 25, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

There is provided a TFT backplane having at least one TFT with oxide active layer and at least one TFT with poly-silicon active layer. In the embodiments of the present disclosure, at least one of the TFTs implementing the circuit of pixels in the active area is an oxide TFT (i.e., TFT with oxide semiconductor) while at least one of the TFTs implementing the driving circuit next to the active area is a LTPS TFT (i.e., TFT with poly-Si semiconductor).

First claim

What is claimed is:

1. A display, comprising:
an array of thin-film-transistors (TFTs) including at least one pair of TFTs consisting of an oxide TFT and a low-temperature-poly-silicon (LTPS) TFT, which are configured to receive a gate signal from the same gate line,
wherein a pixel circuit of the display includes the oxide TFT and the LTPS TFT of the at least one pair of TFTs,
wherein in case a switching TFT directly connected to a data signal line is the oxide TFT, at least one of a switching TFT directly connected to an OLED element and a switching TFT directly connected to a reference voltage line is the LTPS TFT, and
wherein in case the switching TFT directly connected to the data signal line is the LTPS TFT, at least one of the switching TFT directly connected to an OLED element and the switching TFT directly connected to a reference voltage line is the oxide TFT.

2. The display of claim 1 , wherein the pair of the oxide TFT and the LTPS TFT controlled by the same gate line are configured such that each TFT of the pair is activated by the gate signal of the opposite level.

3. The display of claim 2 , wherein the oxide TFT of the pair is an N-Type TFT and the LTPS TFT of the pair is a P-Type TFT.

4. The display of claim 2 , wherein an active layer of the oxide TFT and a gate electrode of the LTPS TFT are made of a metal oxide layer.

5. The display of claim 4 , wherein source/drain electrodes of the LTPS TFT and the oxide TFT are made of the same metal layer.

6. The display of claim 5 , wherein a gate electrode of the oxide TFT is made of the same metal layer as the source/drain electrodes of the oxide TFT.

7. The display of claim 6 , wherein an insulation layer is configured to serve as an interlayer dielectric layer for both the LTPS TFT and the oxide TFT and as a gate insulation layer for the oxide TFT.

8. The display of claim 1 , wherein the pixel circuit includes six transistors and one storage capacitor.

9. The display of claim 1 , the switching TFT connected to the reference voltage line and the switching TFT connected to the OLED element have active layers formed of the same semiconductor material.

10. The display of claim 1 , wherein the oxide TFT of the pair is a P-Type TFT and the LTPS TFT of the pair is an N-Type TFT.

11. A display, comprising:
a first pixel circuit including at least one switching thin-film-transistor (TFT) directly connected to a data signal line; and
a second pixel circuit adjacent to the first pixel circuit including at least one switching TFT directly connected to the data signal line,
wherein the switching TFT of the first pixel circuit and the switching TFT of the second pixel circuit are of different types among an oxide TFT and a low-temperature-poly-silicon (LTPS) TFT, and a gate of the switching TFT of the first pixel circuit and a gate of the switching TFT of the second pixel circuit are directly connected to a single gate line.

12. The display of claim 11 , wherein the oxide TFT and the LTPS TFT connected to the same gate line are configured such that each of the oxide TFT and the LTPS TFT is activated by the gate signal of the opposite level.

13. The display of claim 11 , wherein the oxide TFT is an N-Type TFT and the LTPS TFT is a P-Type TFT.

14. The display of claim 13 , wherein the first pixel circuit of the display includes the N-Type oxide TFT and the second pixel circuit of the display includes the P-Type LTPS TFT.

15. The display of claim 11 , wherein a driving TFT in the first pixel circuit and a driving TFT in the second pixel circuit are different types of TFTs.

Assignees

• Lg Display Co Ltd

Inventors

• Kwon Hoiyong
• Lee Mireum
• Kim Hyoung-Su

Classifications

• H01L27/1225

  Electricity · mapped topic

• H01L27/1251

  Electricity · mapped topic

• H01L27/3276

  Electricity · mapped topic

• H01L27/1248 Primary

  Electricity · mapped topic

• H01L27/1222

  Electricity · mapped topic