TFT, SHIFT REGISTER, SCAN SIGNAL LINE DRIVING CIRCUIT, AND DISPLAY DEVICE

• US 20110007049A1
• Filed: 01/30/2009
• Published: 01/13/2011
• Est. Priority Date: 06/12/2008
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yamasaki, Chikao, Imai, Hajime, Kataoka, Yoshiharu, Kitagawa, Hideki, Kikuchi, Tetsuo, Tanaka, Shinya
• Application Number:
  US12/736,158
• Publication Number:
  US 20110007049A1
• Time in Patent Office: Days
• US Class Current: 345/208
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

A TFT includes, in at least one embodiment, a capacitor formed: so as to have a region where a first capacitor electrode connected to a source electrode and a second capacitor electrode connected to a gate electrode are arranged to be stacked in a thickness direction and mutually opposed across a first dielectric layer therebetween; and so as to have a region where the first capacitor electrode and a third capacitor electrode connected to the gate electrode are arranged to be stacked in the thickness direction and mutually opposed across a second dielectric layer therebetween with a coupling between the first capacitor electrode and the third capacitor electrode and a coupling between the first capacitor electrode and the second capacitor electrode formed over mutually opposite faces of the first capacitor electrode. This realizes a TFT which can save a footprint of a capacitor connected to a TFT body section.

Claims

1. A TFT comprising:

a capacitor formed;

so as to have a region where a first capacitor electrode connected to a source electrode and a second capacitor electrode connected to a gate electrode are arranged to be stacked in a thickness direction and mutually opposed across a first dielectric layer therebetween; and

so as to have a region where the first capacitor electrode and a third capacitor electrode connected to the gate electrode are arranged to be stacked in the thickness direction and mutually opposed across a second dielectric layer therebetween with a coupling between the first capacitor electrode and the third capacitor electrode and a coupling between the first capacitor electrode and the second capacitor electrode formed over mutually opposite faces of the first capacitor electrode.

2. The TFT according to claim 1, wherein

the first capacitor electrode is formed from source metal,

the second capacitor electrode is formed from gate metal, and

the third capacitor electrode is formed from a transparent electrode or a reflecting electrode.

3. The TFT according to claim 1, wherein

the first dielectric layer is a gate dielectric layer, and

the second dielectric layer is a passivation layer.

4. The TFT according to claim 1, wherein

the third capacitor electrode is connected to the gate electrode, through contact with the gate electrode via a contact hole which is formed in a stack of the first and second dielectric layers.

5. The TFT according to claim 1, wherein

the TFT is manufactured with use of amorphous silicon.

6. The TFT according to claim 1, wherein

the TFT is manufactured with use of microcrystalline silicon.

7. A shift register including a plurality of stages composed of transistors, wherein

at least one of the transistors is a TFT according to claim 1.

8. A scanning signal line drive circuit including a shift register according to claim 7, wherein

the shift register is used to generate a scan signal for a display device.

9. The scan signal line driving circuit according to claim 8, wherein

the TFT is an output transistor that outputs the scan signal.

10. The scan signal line driving circuit according to claim 9, wherein

from the first capacitor electrode, a lead-out line connected via a contact hole to a scan signal line is led out.

11. A display device, comprising a scan signal line driving circuit according to claim 8.

12. The display device according to claim 11, wherein

the scan signal line driving circuit is formed on a display panel so as to be monolithically integrated with a display region.

13. A display device, comprising a display panel in which a TFT according to claim 1.