DISPLAY DEVICE

• US 20100072468A1
• Filed: 09/10/2009
• Published: 03/25/2010
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: AKIMOTO, Kengo, YAMAZAKI, Shunpei, UOCHI, Hideki, CHIBA, Yoko, KOMORI, Shigeki, WADA, Rihito
• Granted Patent: US 8,304,765 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: G02F 1/13392 spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
• CPC Class Codes: G02F 1/13398 Spacer materials; Spacer properties
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G09G 2300/0804 Sub-multiplexed active matrix panel, i.e. wherein one active driving circuit is used at pixel level for multiple image producing elements
• 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 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 27/1244 for preventing breakage, peeling or short circuiting
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/8052 Cathodes

Abstract

A display device includes a pixel portion in which a pixel electrode layer is arranged in a matrix, and an inverted staggered thin film transistor having a combination of at least two kinds of oxide semiconductor layers with different amounts of oxygen is provided corresponding to the pixel electrode layer. In the periphery of the pixel portion in this display device, a pad portion is provided to be electrically connected to a common electrode layer formed on a counter substrate through a conductive layer made of the same material as the pixel electrode layer. One objection of our invention to prevent a defect due to separation of a thin film in various kinds of display devices is realized, by providing a structure suitable for a pad portion provided in a display panel.

Claims

1. A display device comprising:

a first substrate having a pixel portion and a common connection portion;

a second substrate having a first conductive layer; and

a conductive particle interposed between the first substrate and the second substrate,

wherein the pixel portion comprises;

a gate electrode over the first substrate;

a first insulating layer over the gate electrode;

a first oxide semiconductor layer over the first insulating layer;

a second oxide semiconductor layer and a third oxide semiconductor layer over the first oxide semiconductor layer;

a second conductive layer over the first insulating layer and the second oxide semiconductor layer;

a third conductive layer over the first insulating layer and the third oxide semiconductor layer;

a second insulating layer over the second and third conductive layers and the first oxide semiconductor layer, the second insulating layer having a first contact hole formed over the third conductive layer; and

a fourth conductive layer over the second insulating layer and electrically connected to the third conductive layer through the first contact hole,

wherein the common connection portion comprises;

a third insulating layer over the first substrate;

a fifth conductive layer over the third insulating layer;

a fourth insulating layer having a second contact hole formed over the fifth conductive layer; and

a sixth conductive layer over the fourth insulating layer and electrically connected to the fifth conductive layer through the second contact hole,

wherein the sixth conductive layer in the common connection portion is electrically connected to the first conductive layer through the conductive particle,

wherein the second conductive layer, the third conductive layer, and the fifth conductive layer are formed of the same material,

wherein the fourth conductive layer and the sixth conductive layer are formed of the same material,

wherein the first insulating layer and the third insulating layer are formed of the same material, and

wherein the second insulating layer and the fourth insulating layer are formed of the same material.

2. The display device according to claim 1, wherein the common connection portion further comprises a fourth oxide semiconductor layer interposed between the third insulating layer and the fifth conductive layer, and

wherein the first oxide semiconductor layer and the fourth oxide semiconductor layer are formed of the same material.

3. The display device according to claim 1, wherein the common connection portion further comprises a fifth oxide semiconductor layer interposed between the third insulating layer and the fifth conductive layer, and

wherein the second oxide semiconductor layer, the third oxide semiconductor layer, and the fifth oxide semiconductor layer are formed of the same material.

4. The display device according to claim 1, wherein the first to third oxide semiconductor layers include indium, gallium, and zinc.

5. The display device according to claim 1, wherein the second conductive layer, the third conductive layer and the fifth conductive layer include Ti.

6. The display device according to claim 1, wherein the conductive particle is included in a sealant, and

wherein the first substrate is fixed to the second substrate with the sealant.

7. The display device according to claim 1, wherein the first oxide semiconductor layer has a higher oxygen concentration than the second and third oxide semiconductor layers.

8. A display device comprising:

a first substrate having a pixel portion and a common connection portion;

a second substrate having a first conductive layer; and

a conductive particle interposed between the first substrate and the second substrate,

wherein the pixel portion comprises;

a gate electrode over the first substrate;

a first insulating layer over the gate electrode;

a first oxide semiconductor layer over the first insulating layer;

a second oxide semiconductor layer and a third oxide semiconductor layer over the first oxide semiconductor layer;

a second conductive layer over the first insulating layer and the second oxide semiconductor layer;

a third conductive layer over the first insulating layer and the third oxide semiconductor layer;

a second insulating layer over the second and third conductive layers and the first oxide semiconductor layer, the second insulating layer having a first contact hole formed over the third conductive layer; and

a fourth conductive layer over the second insulating layer and electrically connected to the third conductive layer through the first contact hole,

wherein the common connection portion comprises;

a fifth conductive layer over the first substrate;

a third insulating layer having a second contact hole, the third insulating layer formed over the fifth conductive layer; and

a sixth conductive layer over the third insulating layer and electrically connected to the fifth conductive layer through the second contact hole,

wherein the sixth conductive layer in the common connection portion is electrically connected to the first conductive layer through the conductive particle,

wherein the gate electrode and the fifth conductive layer are formed of the same material,

wherein the fourth conductive layer and the sixth conductive layer are formed of the same material, and

wherein the first insulating layer and the third insulating layer are formed of the same material.

9. The display device according to claim 8, wherein the first to third oxide semiconductor layers include indium, gallium, and zinc.

10. The display device according to claim 8, wherein the second conductive layer and the third conductive layer include Ti.

11. The display device according to claim 8, wherein the conductive particle is included in a sealant, and

wherein the first substrate is fixed to the second substrate with the sealant.

12. The display device according to claim 8, wherein the common connection portion further comprises a fourth insulating layer having a third contact hole,

wherein the fourth insulating layer is interposed between the third insulating layer and the sixth conductive layer,

wherein the second insulating layer and the fourth insulating layer are formed of the same material, and

wherein the sixth conductive layer is electrically connected to the fifth conductive layer through the second contact hole and the third contact hole.

13. The display device according to claim 8, wherein the first oxide semiconductor layer has a higher oxygen concentration than the second and third oxide semiconductor layers.

14. A display device comprising:

a first substrate having a pixel portion and a common connection portion;

a second substrate having a first conductive layer; and

a conductive particle interposed between the first substrate and the second substrate,

wherein the pixel portion comprises;

a gate electrode over the first substrate;

a first insulating layer over the gate electrode;

a first oxide semiconductor layer over the first insulating layer;

a second oxide semiconductor layer and a third oxide semiconductor layer over the first oxide semiconductor layer;

a second conductive layer over the first insulating layer and the second oxide semiconductor layer;

a third conductive layer over the first insulating layer and the third oxide semiconductor layer;

a second insulating layer over the second and third conductive layers and the first oxide semiconductor layer, the second insulating layer having a first contact hole formed over the third conductive layer; and

a fourth conductive layer over the second insulating layer and electrically connected to the third conductive layer through the first contact hole,

wherein the common connection portion comprises;

a fifth conductive layer over the first substrate;

a third insulating layer over the fifth conductive layer;

a sixth conductive layer over the third insulating layer;

a fourth insulating layer having a second contact hole formed over the sixth conductive layer; and

a seventh conductive layer over the fourth insulating layer and electrically connected to the sixth conductive layer through the second contact hole,

wherein the seventh conductive layer in the common connection portion is electrically connected to the first conductive layer through the conductive particle,

wherein the gate electrode and the fifth conductive layer are formed of the same material,

wherein the second conductive layer, the third conductive layer, and the sixth conductive layer are formed of the same material,

wherein the fourth conductive layer and the seventh conductive layer are formed of the same material,

wherein the first insulating layer and the third insulating layer are formed of the same material, and

wherein the second insulating layer and the fourth insulating layer are formed of the same material.

15. The display device according to claim 14, wherein the common connection portion further comprises a fourth oxide semiconductor layer interposed between the third insulating layer and the sixth conductive layer, and

wherein the first oxide semiconductor layer and the fourth oxide semiconductor layer are formed of the same material.

16. The display device according to claim 14, wherein the common connection portion further comprises a fifth oxide semiconductor layer interposed between the third insulating layer and the sixth conductive layer, and

wherein the second oxide semiconductor layer, the third oxide semiconductor layer, and the fifth oxide semiconductor layer are formed of the same material.

17. The display device according to claim 14, wherein the first to third oxide semiconductor layers include indium, gallium, and zinc.

18. The display device according to claim 14, wherein the second conductive layer, the third conductive layer, and the sixth conductive layer include Ti.

19. The display device according to claim 14, wherein the conductive particle is included in a sealant, and

wherein the first substrate is fixed to the second substrate with the sealant.

20. The display device according to claim 14, wherein a potential of the fifth conductive layer and a potential of the sixth conductive layer are different from each other.

21. The display device according to claim 14, wherein the first oxide semiconductor layer has a higher oxygen concentration than the second and third oxide semiconductor layers.

22. A display device comprising:

a first substrate having a pixel portion and a common connection portion;

a second substrate having a first conductive layer; and

a conductive particle interposed between the first substrate and the second substrate,

wherein the pixel portion comprises;

a gate electrode over the first substrate;

a first insulating layer over the gate electrode;

an oxide semiconductor layer over the first insulating layer;

a second conductive layer on the oxide semiconductor layer;

a third conductive layer on the oxide semiconductor layer;

a second insulating layer on the second and third conductive layers and on the oxide semiconductor layer, the second insulating layer having a first contact hole formed over the third conductive layer; and

a fourth conductive layer over the second insulating layer and electrically connected to the third conductive layer through the first contact hole,

wherein the common connection portion comprises;

a third insulating layer over the first substrate;

a fifth conductive layer over the third insulating layer;

a fourth insulating layer having a second contact hole formed over the fifth conductive layer; and

a sixth conductive layer over the fourth insulating layer and electrically connected to the fifth conductive layer through the second contact hole,

wherein the sixth conductive layer in the common connection portion is electrically connected to the first conductive layer through the conductive particle,

wherein the second conductive layer, the third conductive layer, and the fifth conductive layer are formed of the same material,

wherein the fourth conductive layer and the sixth conductive layer are formed of the same material,

wherein the first insulating layer and the third insulating layer are formed of the same material, and

wherein the second insulating layer and the fourth insulating layer are formed of the same material.

23. The display device according to claim 22, wherein the oxide semiconductor layers include indium, gallium, and zinc.

24. The display device according to claim 22, wherein the second conductive layer, the third conductive layer, and the fifth conductive layer include Ti.

25. The display device according to claim 22, wherein the conductive particle is included in a sealant, and

wherein the first substrate is fixed to the second substrate with the sealant.

26. The display device according to claim 22, wherein the common connection portion further comprises a seventh conductive layer interposed between the first substrate and the third insulating layer, and

wherein the gate electrode and the seventh conductive layer are formed of the same material.

27. The display device according to claim 26, wherein the fifth conductive layer is electrically connected to the seventh conductive layer.

28. The display device according to claim 22, wherein the second and third conductive layers are made of a material such as titanium film.