Thin film transistors for circuits for use in display devices

Patent metadata

Field	Value
Publication number	US-12354557-B2
Application number	US-202118556460-A
Country	US
Kind code	B2
Filing date	May 7, 2021
Priority date	May 7, 2021
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

Disclosed herein is a device including a driving thin film transistor. The driving thin film transistor includes a metal oxide channel, a source electrode in contact with the driving metal oxide channel, and a top gate electrode disposed above the metal oxide channel and physically connected to the driving source electrode.

First claim

What is claimed is:

1. A device comprising:
a pixel circuit, the pixel circuit comprising:
a driving thin film transistor (TFT), the driving TFT comprising:
a driving channel;
an inter layer dielectric (ILD) layer disposed over the driving channel;
a driving source electrode disposed through the ILD layer to contact an upper surface of the driving channel, the driving source electrode coupled to a source voltage via a source electrode path of wiring; and
a driving top gate electrode disposed above the driving channel and electrically connected to the driving source electrode and the source voltage via a top gate electrode path of wiring coupled to the source electrode path; and

a first switching TFT connected to a scan line; and

a gate on array (GOA) circuit, the GOA circuit comprising a second switching TFT and a third switching TFT, wherein the second switching TFT and the third switching TFT are connected to the scan line.

2. The device of claim 1 , wherein each of the switching TFTs comprise:
a switching metal oxide (MO) channel; and
a switching top gate electrode disposed above the switching MO channel.

3. The device of claim 2 , wherein at least one of the switching TFTs comprise a switching bottom gate electrode electrically connected to the switching top gate electrode.

4. The device of claim 1 , wherein the driving TFT further comprises a driving bottom gate electrode, wherein a gate bias is applied to the driving bottom gate electrode.

5. A device comprising a driving thin film transistor (TFT) comprising:
a first TFT comprising:
a first channel,
a first bottom gate electrode disposed below the first channel, and
a gate insulator layer disposed between the first channel and the first bottom gate electrode, and

a second TFT adjacent to the first TFT comprising:
a second channel, and
a second bottom gate electrode disposed below the second channel and electrically connected to the first bottom gate electrode of the first TFT, wherein
the gate insulator layer extends from the first TFT and is disposed between the second channel and the second bottom gate electrode and the first bottom gate electrode and the second bottom gate electrode are electrically connected to the same voltage source.

6. The device of claim 5 , wherein the first TFT comprises a first top gate electrode disposed above the first channel.

7. The device of claim 5 , further comprising one or more switching TFTs, each switching TFT is a top gate electrode TFT, wherein the top gate electrode TFT is free of bottom gate electrodes.

8. The device of claim 5 , further comprising one or more switching TFTs, each switching TFT comprising:
a switching bottom gate electrode;
a switching metal oxide (MO) channel disposed above the switching bottom gate electrode; and
a switching top gate electrode disposed above the switching MO channel, wherein the switching top gate electrode is electrically connected to the switching bottom gate electrode.

9. The device of claim 8 , wherein the device comprises a gate driver on array (GOA) circuit.

10. The device of claim 8 , wherein the device comprises a pixel circuit.

11. The device of claim 5 further comprising a top gate insulating layer disposed over the first channel and extending over the second channel.

12. The device of claim 5 , further comprising a first top gate insulating layer disposed over the first channel and a second top gate insulating layer disposed over the second channel.

13. A device comprising a driving thin film transistor (TFT) comprising:
a first TFT comprising:
a first channel,
a gate insulator layer disposed below the first channel, and
a first top gate electrode disposed above the first channel; and

a second TFT adjacent to the first TFT comprising:
a second channel,
the gate insulator layer disposed below the second channel, and
a second top gate electrode disposed above the second channel and electrically connected to the first top gate electrode of the first TFT, wherein
the gate insulator layer extends from the first TFT and is disposed between the second channel and the second bottom gate electrode and the first top gate electrode and the second top gate electrode are electrically connected to the same voltage source.

14. The device of claim 13 , further comprising one or more switching TFTs, each switching TFT comprising:
a switching channel; and
a switching top gate electrode disposed above the switching channel.

15. The device of claim 14 , further comprising one or more switching TFTs, each switching TFT comprising a switching bottom gate electrode disposed below the switching channel, wherein the switching top gate electrode is electrically connected to the switching bottom gate electrode.

16. The device of claim 13 , wherein at least one of the first channel and the second channel is a metal oxide containing layer comprising at least one of indium, zinc, gallium, oxygen, aluminum, tin, In—Zn—O, In—Sn—O, In—Zn—Sn—O, In—Ga—O, In—Ga—Zn—O, In—Ga—Sn—O, In—Ga—Zn—Sn—O, or a combination thereof.

17. The device of claim 13 , wherein at least one of the first channel and the second channel is a low temperature poly silicon (LTPS) single layer.

18. The device of claim 13 , wherein at least one of the first channel or the second channel, or both the first and second channel each consist of a single layer.

19. The device of claim 13 , wherein at least one of the first channel or the second channel comprise two or more layers, each layer having different electron mobility.

20. The device of claim 1 , wherein the ILD layer extends across an upper surface of the driving top gate electrode.

Assignees

• Applied Materials Inc

Inventors

• Yim Dong Kil
• Choi Soo Young
• Kim Jung Bae

Classifications

• H10D30/504

  wherein the stacked channels have different properties · CPC title

• H10D30/674

  characterised by the active materials · 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

• H10D30/6755

  Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate · CPC title

• G09G2320/0214

  with crosstalk due to leakage current of pixel switch in active matrix panels · CPC title