DISPLAY DEVICE

• US 20090101895A1
• Filed: 10/17/2008
• Published: 04/23/2009
• Est. Priority Date: 10/19/2007
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Hatano, Mutsuko, Sato, Takeshi, Kawamura, Tetsufumi
• Granted Patent: US 7,737,517 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A display device includes a pixel including: a gate line; a gate insulating film; a substrate; a data line; a pixel electrode; a semiconductor layer formed on the gate line and the gate insulating film; a protective film formed on the data line, the pixel electrode, and the semiconductor layer; and a thin film transistor. A portion of the gate line also serves as a gate electrode of the thin film transistor. A portion of the data line also serves as a drain electrode of the thin film transistor. A portion of the pixel electrode also serves as a source electrode of the thin film transistor. The semiconductor layer is formed of an oxide semiconductor layer. The oxide semiconductor layer is directly connected to the drain electrode and the source electrode, and the data line and the pixel electrode are formed of different conductive films.

Claims

1. A display device, comprising a pixel comprising:

a gate line;

a gate insulating film;

a substrate on which the gate line and the gate insulating film are sequentially formed;

a data line formed on the gate insulating film;

a pixel electrode formed on the gate insulating film;

a semiconductor layer formed on the gate insulating film over a gate electrode;

a protective film formed on the data line, the pixel electrode, and the semiconductor layer; and

a thin film transistor,

a portion of the gate line also serving as a gate electrode of the thin film transistor,

a portion of the data line also serving as a drain electrode of the thin film transistor,

a portion of the pixel electrode also serving as a source electrode of the thin film transistor,

the semiconductor layer comprising an oxide semiconductor layer,

wherein the oxide semiconductor layer is directly connected to the drain electrode and the source electrode, and the data line and the pixel electrode comprise different conductive films.

2. A display device according to claim 1, wherein the oxide semiconductor layer is formed on the drain electrode and the source electrode.

3. A display device according to claim 1, wherein the oxide semiconductor layer is formed on one of the drain electrode and the source electrode, and another one of the drain electrode and the source electrode is formed on the oxide semiconductor layer.

4. A display device according to claim 1, wherein the drain electrode and the source electrode are formed on the oxide semiconductor layer.

5. A display device according to claim 1, wherein the data line comprises one of metal, a laminated film of metal and another conductive film, and a laminated film of metal and a semiconductor film, and the pixel electrode comprises a transparent conductive film.

6. A display device according to claim 1, wherein at least one of the drain electrode and the source electrode overlaps the gate electrode in plan view.

14. A display device according to claim 1, wherein a part of a region of the oxide semiconductor layer is modified to have low resistance, and at least one of the data line and the pixel electrode is connected to the part of the region modified to have low resistance.

19. A display device according to claim 1, further comprising a comb-shaped pixel electrode disposed to overlap a flat-plate like counter electrode via an insulating film,

wherein the flat-plate like counter electrode is supplied with a voltage signal serving as a reference with respect to a video signal supplied to the comb-shaped pixel electrode via a common line.

7. A display device, comprising a pixel comprising:

a gate line;

a gate insulating film;

a substrate on which the gate line and the gate insulating film are sequentially formed;

a data line formed on the gate insulating film;

a semiconductor layer formed on the gate insulating film over a gate electrode;

a protective film formed on the gate insulating film, the data line, and the semiconductor layer;

a thin film transistor; and

a pixel electrode formed on the protective film, the pixel electrode being connected to a source of the thin film transistor via a through hole formed in the protective film,

a portion of the gate line also serving as a gate electrode of the thin film transistor,

a portion of the data line also serving as a drain electrode of the thin film transistor,

a portion of the pixel electrode also serving as a source electrode of the thin film transistor,

the semiconductor layer comprising an oxide semiconductor layer,

wherein the semiconductor layer is directly connected to the drain electrode and the source electrode.

8. A display device according to claim 7, wherein the oxide semiconductor layer is formed on the drain electrode, and the protective film is formed on the drain electrode and the oxide semiconductor layer.

9. A display device according to claim 7, wherein the drain electrode is formed on the oxide semiconductor layer, and the protective film is formed on the oxide semiconductor layer and the drain electrode.

10. A display device according to claim 7, wherein:

the protective film is formed on the oxide semiconductor layer;

the data line is formed on the protective film, the data line being connected to a drain of the thin film transistor via another through hole formed in the protective film; and

the pixel electrode is formed on the protective film, the pixel electrode being connected to the source of the thin film transistor via the through hole formed in the protective film.

11. A display device according to claim 10, wherein the data line and the pixel electrode comprise the same conductive film.

12. A display device according to claim 7, wherein:

the data line comprises one of metal, a laminated film of metal and another conductive film, and a laminated film of metal and a semiconductor film; and

the pixel electrode comprises a transparent conductive film.

13. A display device according to claim 7, wherein the gate electrode and at least one of the drain electrode and the source electrode overlap with each other.

15. A display device according to claim 7, wherein a part of region of the oxide semiconductor layer is modified to have low resistance, and at least one of the data line and the pixel electrode is connected to the part of the region modified to have low resistance.

20. A display device according to claim 7, further comprising a comb-shaped pixel electrode disposed to overlap a flat-plate like counter electrode via an insulating film,

wherein the flat-plate like counter electrode is supplied with a voltage signal serving as a reference with respect to a video signal supplied to the comb-shaped pixel electrode via a common line.

16. A display device, comprising a pixel comprising:

a gate line;

a gate insulating film;

a substrate on which the gate line and the gate insulating film are sequentially formed;

a data line formed on the gate insulating film;

a pixel electrode formed on the gate insulating film;

a semiconductor layer formed on the gate insulating film over a gate electrode;

a protective layer formed on the data line, the pixel electrode, and the semiconductor layer; and

a thin film transistor,

a portion of the gate line also serving as a gate electrode of the thin film transistor,

a portion of the data line also serving as a drain electrode of the thin film transistor,

a portion of the pixel electrode also serving as a source electrode of the thin film transistor,

the semiconductor layer comprising an oxide semiconductor layer,

wherein a part of a region of the oxide semiconductor layer is modified to have low resistance to integrally form at least one of the data line and the pixel electrode with the part of the region modified to have low resistance.

17. A display device according to claim 16, wherein:

the data line comprises the part of the region of the oxide semiconductor layer modified to have low resistance, and the protective film is formed on the oxide semiconductor layer; and

the pixel electrode is formed on the protective film, the pixel electrode being connected to a source of the thin film transistor via a through hole formed in the protective film.

18. A display device according to claim 16, wherein:

the drain electrode is formed to overlap the gate electrode;

the oxide semiconductor layer is formed on the drain electrode; and

a part of a region of the oxide semiconductor layer is made to have low resistance to form the pixel electrode.

21. A display device according to claim 16, further comprising a comb-shaped pixel electrode disposed to overlap a flat-plate like counter electrode via an insulating film,

wherein the flat-plate like counter electrode is supplied with a voltage signal serving as a reference with respect to a video signal supplied to the comb-shaped pixel electrode via a common line.