CIRCUIT BOARD AND DISPLAY DEVICE

• US 20100051959A1
• Filed: 04/25/2008
• Published: 03/04/2010
• Est. Priority Date: 08/24/2007
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Moriwaki, Hiroyuki
• Granted Patent: US 8,304,781 B2
• Time in Patent Office: Days
• US Class Current: 257/72
• 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 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate

Abstract

The present invention provides a circuit board that includes high-performance thin film transistors whose characteristics are hardly varied thereamong in a monolithic circuit and also provide a display device including the circuit board. The circuit board of the present invention is a circuit board including a monolithic circuit including a thin film transistor on a substrate, wherein the thin film transistor includes a semiconductor layer, a gate insulating film, and a gate electrode, stacked in this order, a portion where the gate electrode overlaps with the semiconductor layer has an area of 40 μm² or less, and the gate electrode has a thickness of 300 nm or less.

Claims

1. A circuit board comprising a monolithic circuit including a thin film transistor on a substrate,

wherein the thin film transistor includes a semiconductor layer, a gate insulating film, and a gate electrode, stacked in this order,

a portion where the gate electrode overlaps with the semiconductor layer has an area of 40 μ

m² or less, and

the gate electrode has a thickness of 300 nm or less.

2. The circuit board according to claim 1,

wherein the gate electrode has a thickness of 200 nm or less.

3. The circuit board according to claim 1,

wherein the circuit board includes a gate wiring connected to the gate electrode, and

the gate wiring is constituted by a wiring layer and a layer structure that is the same as a layer structure of the gate electrode.

4. The circuit board according to claim 1,

wherein the gate insulating film contains silicon oxide.

5. The circuit board according to claim 1, wherein the gate insulating film contains silicon nitride.

6. A display device comprising the circuit board according to claim 1.