Semiconductor device having light-shielded thin film transistor

• US 7,023,502 B2
• Filed: 03/03/2005
• Issued: 04/04/2006
• Est. Priority Date: 09/04/1996
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Teramoto, Satoshi, Zhang, Hongyong
• Primary Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US11/069,982
• Publication Number:
  US 20050151891A1
• Time in Patent Office: 397 Days
• Field of Search: 349/38, 349/39, 349/42, 349/43, 349/48, 349/110, 349/111, 349/138, 257/59, 257/72
• US Class Current: 349/43
• 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

Abstract

The present invention provides an active matrix type display device having a high aperture ratio and a required auxiliary capacitor. A source line and a gate line are overlapped with part of a pixel electrode. This overlapped region functions to be a black matrix. Further, an electrode pattern made of the same material as the pixel electrode is disposed to form the auxiliary capacitor by utilizing the pixel electrode. It allows a required value of auxiliary capacitor to be obtained without dropping the aperture ratio. Also, it allows the electrode pattern to function as a electrically shielding film for suppressing the cross-talk between the source and gate lines and the pixel electrode.

Claims

1. A semiconductor device comprising:

at least one source line over a substrate;

at least one gate line over the substrate, across the source line; and

at least one pixel over the substrate arranged in a matrix array at intersections of the source line and the gate line, the pixel comprising;

an active layer comprising source and drain regions and first and second channel regions between the source and drain regions, wherein one of the source and drain regions is connected to the source line;

an electrode pattern covering and extending along the source and gate lines; and

a pixel electrode formed over the electrode pattern connected to another one of the source and drain regions, ends of the pixel electrode overlapping the source and gate lines with the electrode pattern interposed therebetween,

wherein a portion of the source line covers the first channel region so that the first channel region is light shielded while the second channel region is not covered by any portion of the source line.

2. A semiconductor device according to claim 1, wherein the electrode pattern comprises a transparent material.

3. A semiconductor device according to claim 1, wherein a material of the electrode pattern is a same as that of the pixel electrode.

4. A semiconductor device according to claim 1, wherein an auxiliary capacitor is formed between the electrode pattern and the pixel electrode.

5. A semiconductor device comprising:

at least one source line over a substrate;

at least one gate line over the substrate, across the source line; and

at least one pixel over the substrate arranged in a matrix array at intersections of the source line and the gate line, the pixel comprising;

an active layer comprising source and drain regions and first and second channel regions between the source and drain regions, wherein one of the source and drain regions is connected to the source line;

an electrode pattern covering and extending along the source and gate lines; and

a pixel electrode formed over the electrode pattern connected to another one of the source and drain regions, ends of the pixel electrode overlapping the source and gate lines with the electrode pattern interposed therebetween,

wherein a contact portion in the source or drain region of first thin film transistor of the source line and the active layer does not overlap with the pixel electrode;

wherein a portion of the source line covers the first channel region so that the first channel region is light shielded while the second channel region is not covered by any portion of the source line.

6. A semiconductor device according to claim 5, wherein the electrode pattern comprises a transparent material.

7. A semiconductor device according to claim 5, wherein a material of the electrode pattern is a same as that of the pixel electrode.

8. A semiconductor device according to claim 5, wherein an auxiliary capacitor is formed between the electrode pattern and the pixel electrode.

9. A semiconductor device comprising:

at least one source line over a substrate;

at least one gate line over the substrate, across the source line; and

at least one pixel over the substrate arranged in a matrix array at intersections of the source line and the gate line, the pixel comprising;

an active layer comprising source and drain regions and first and second channel regions between the source and drain regions, wherein one of the source and drain regions is connected to the source line;

an electrode pattern covering and extending along the source and gate lines; and

a pixel electrode formed over the electrode pattern connected to another one of the source and drain regions, ends of the pixel electrode overlapping the source and gate lines with the electrode pattern interposed therebetween,

wherein the electrode pattern covers an intersection of the source and gate lines;

wherein a portion of the source line covers the first channel region so that the first channel region is light shielded while the second channel region is not covered by any portion of the source line.

10. A semiconductor device according to claim 9, wherein the electrode pattern comprises a transparent material.

11. A semiconductor device according to claim 9, wherein a material of the electrode pattern is a same as that of the pixel electrode.

12. A semiconductor device according to claim 9, wherein an auxiliary capacitor is formed between the electrode pattern and the pixel electrode.

13. A semiconductor device comprising:

at least one source line over a substrate;

at least one gate line over the substrate, across the source line; and

at least one pixel over the substrate arranged in a matrix array at intersections of the source line and the gate line, the pixel comprising;

an active layer comprising source and drain regions and first and second channel regions between the source and drain regions, wherein one of the source and drain regions is connected to the source line;

an electrode pattern covering and extending along the source and gate lines; and

a pixel electrode formed over the electrode pattern connected to another one of the source and drain regions, ends of the pixel electrode overlapping the source and gate lines with the electrode pattern interposed therebetween,

wherein the electrode pattern functions as a shield film for electrically shielding the source and gate lines from the pixel electrode;

wherein a portion of the source line covers the first channel region so that the first channel region is light shielded while the second thin film transistor the second channel region is not covered by any portion of the source line.

14. A semiconductor device according to claim 13, wherein the electrode pattern comprises a transparent material.

15. A semiconductor device according to claim 13, wherein a material of the electrode pattern is a same as that of the pixel electrode.

16. A semiconductor device according to claim 13, wherein an auxiliary capacitor is formed between the electrode pattern and the pixel electrode.