Semiconductor device comprising pixel portion

• US 8,552,431 B2
• Filed: 08/08/2012
• Issued: 10/08/2013
• 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, Atsugo
• Primary Examiner(s): NGO, NGAN V
• Application Number:
  US13/569,445
• Publication Number:
  US 20120305924A1
• Time in Patent Office: 426 Days
• Field of Search: 257/59, 257/72, 257/296, 257/350
• 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 scanning line and a source wiring crossed with each other over a substrate; and

a semiconductor layer including a first portion, a second portion and a third portion between the first portion and the second portion,

wherein the first portion extends in parallel with the scanning line and the second portion extends in parallel with the source wiring,

wherein the first portion overlaps the scanning line and the second portion overlaps the source wiring, and

wherein the third portion is narrower than the first portion and the second portion.

2. The display device according to claim 1, further comprising a first insulating film between the scanning line and the semiconductor layer, a second insulating film between the semiconductor layer and a gate electrode, and a third insulating film between the gate electrode and the source wiring.

3. The display device according to claim 1, further comprising a capacitor wiring overlapping the first portion and the second portion.

4. The display device according to claim 3, wherein a width of the source wiring is smaller than a width of the capacitor wiring.

5. The display device according to claim 3, wherein the capacitor wiring contains at least one of poly-silicon and tungsten silicide.

6. 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.

13. The display device according to claim 1, wherein each of the first portion and the second portion is obliquely-connected to the third portion.

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

a scanning line and a source wiring crossed with each other over a substrate; and

a semiconductor layer including a first portion, a second portion and a third portion between the first portion and the second portion,

wherein the first portion extends in parallel with the scanning line and the second portion extends in parallel with the source wiring,

wherein the first portion overlaps the scanning line and the second portion overlaps the source wiring,

wherein the first portion and the second portion extend at a right angle to each other, and

wherein the third portion is narrower than the first portion and the second portion.

8. The display device according to claim 7, further comprising a first insulating film between the scanning line and the semiconductor layer, a second insulating film between the semiconductor layer and a gate electrode, and a third insulating film between the gate electrode and the source wiring.

9. The display device according to claim 7, further comprising a capacitor wiring overlapping the first portion and the second portion.

10. The display device according to claim 9, wherein a width of the source wiring is smaller than a width of the capacitor wiring.

11. The display device according to claim 9, wherein the capacitor wiring contains at least one of poly-silicon and tungsten silicide.

12. The display device according to claim 7, 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.

14. The display device according to claim 7, wherein each of the first portion and the second portion is obliquely-connected to the third portion.