Display device comprising pixel

• US 8,933,455 B2
• Filed: 09/05/2013
• Issued: 01/13/2015
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shibata, Hiroshi, Isobe, Atsuo
• Primary Examiner(s): NGO, NGAN V
• Application Number:
  US14/018,463
• Publication Number:
  US 20140021476A1
• Time in Patent Office: 495 Days
• Field of Search: 257/59, 257/72, 257/350, 257/435
• US Class Current: 257/59
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• 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
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/786 Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals

Abstract

To provide a liquid crystal display device having high quality display by obtaining a high aperture ratio while securing a sufficient storage capacitor (Cs), and at the same time, by dispersing a load (a pixel writing-in electric current) of a capacitor wiring in a timely manner to effectively reduce the load. A scanning line is formed on a different layer from a gate electrode and the capacitor wiring is arranged so as to be parallel with a signal line. Each pixel is connected to the individually independent capacitor wiring via a dielectric. Therefore, variations in the electric potential of the capacitor wiring caused by a writing-in electric current of a neighboring pixel can be avoided, whereby obtaining satisfactory display images.

Claims

1. A display device comprising a pixel portion, the pixel portion comprising:

a first conductive film over a substrate;

a first insulating film over the first conductive film;

a semiconductor layer including a channel forming region over the first insulating film;

a gate insulating film over the semiconductor layer;

a gate electrode over the gate insulating film;

a second insulating film over the gate electrode;

an electrode over the second insulating film, wherein the electrode is electrically connected to the semiconductor layer;

a second conductive film over the electrode;

a third insulating film over the electrode; and

a pixel electrode over the third insulating film.

2. The display device according to claim 1, wherein the first conductive film is a scanning line electrically connected to the gate electrode.

3. The display device according to claim 1, wherein each of the first conductive film and the second conductive film is a light-shielding layer.

4. The display device according to claim 1, wherein the display device is incorporated in one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player using a recording medium and a digital camera.

5. A display device comprising a pixel portion, the pixel portion comprising:

a first conductive film including tungsten over a substrate;

a first insulating film over the first conductive film;

a semiconductor layer including a channel forming region over the first insulating film;

a gate insulating film over the semiconductor layer;

a gate electrode over the gate insulating film;

a second insulating film over the gate electrode;

an electrode including aluminum and titanium over the second insulating film, wherein the electrode is electrically connected to the semiconductor layer;

a second conductive film over the electrode;

a third insulating film over the electrode; and

a pixel electrode over the third insulating film.

6. The display device according to claim 5, wherein the first conductive film is a scanning line electrically connected to the gate electrode.

7. The display device according to claim 5, wherein each of the first conductive film and the second conductive film is a light-shielding layer.

8. The display device according to claim 5, wherein the display device is incorporated in one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player using a recording medium and a digital camera.

9. A display device comprising a pixel portion, the pixel portion comprising:

a first conductive film over a substrate;

a first insulating film over the first conductive film;

a semiconductor layer including a channel forming region over the first insulating film, wherein an entire region of the channel forming region overlaps the first conductive film;

a gate insulating film over the semiconductor layer;

a gate electrode over the gate insulating film;

a second insulating film over the gate electrode;

an electrode over the second insulating film, wherein the electrode is electrically connected to the semiconductor layer;

a second conductive film over the electrode;

a third insulating film over the electrode; and

a pixel electrode over the third insulating film.

10. The display device according to claim 9, wherein the first conductive film is a scanning line electrically connected to the gate electrode.

11. The display device according to claim 9, wherein each of the first conductive film and the second conductive film is a light-shielding layer.

12. The display device according to claim 9, wherein the display device is incorporated in one selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player using a recording medium and a digital camera.