Liquid crystal display device and method for manufacturing the same
Provided is a method to manufacture a liquid crystal display device in which a contact hole for the electrical connection of the pixel electrode and one of the source and drain electrode of a transistor and a contact hole for the processing of a semiconductor layer are formed simultaneously. The method contributes to the reduction of a photography step. The transistor includes an oxide semiconductor layer where a channel formation region is formed.
1. A display device comprising:
a pixel portion comprising:
a first conductive layer comprising a region in contact with an insulating surface;
a first insulating layer comprising a region in contact with an upper surface of the first conductive layer;
a first oxide semiconductor layer comprising a region in contact with an upper surface of the first insulating layer, the first oxide semiconductor layer comprising a channel formation region of a transistor;
a second conductive layer comprising a region in contact with an upper surface of the first oxide semiconductor layer;
a second insulating layer over the first oxide semiconductor layer and the second conductive layer; and
a third conductive layer electrically connected to the second conductive layer, the third conductive layer comprising a region over the second insulating layer; and
a connecting portion comprising:
a fourth conductive layer comprising a region in contact with the insulating surface, the fourth conductive layer comprising the same material as the first conductive layer;
the first insulating layer comprising a region in contact with an upper surface of the fourth conductive layer;
a second oxide semiconductor layer comprising a region in contact with the upper surface of the first insulating layer; and
a fifth conductive layer over the second oxide semiconductor layer, the fifth conductive layer comprising the same material as the third conductive layer,
wherein the first conductive layer is configured to serve as a gate electrode of the transistor,
wherein the second conductive layer is configured to serve as one of a source electrode and a drain electrode of the transistor,
wherein each of the first conductive layer and the fourth conductive layer comprises a stacked structure comprising a titanium layer and a copper layer over the titanium layer,
wherein the first insulating layer and the second oxide semiconductor layer comprise a contact hole, and
wherein the fifth conductive layer is electrically connected to the fourth conductive layer through the contact hole.
2. The display device according to claim 1 , wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises indium, gallium, zinc, and oxygen.
3. The display device according to claim 1 , further comprising:
a liquid crystal material over the third conductive layer.
4. The display device according to claim 1 , wherein the second conductive layer overlaps with the first conductive layer.
5. The display device according to claim 1 , wherein the channel formation region comprises crystals with c-axis alignment.
6. A display device comprising:
a pixel portion comprising:
a first conductive layer comprising a region in contact with an insulating surface;
a first insulating layer comprising a region in contact with an upper surface of the first conductive layer;
a first oxide semiconductor layer comprising a region in contact with an upper surface of the first insulating layer, the first oxide semiconductor layer comprising a channel formation region of a transistor;
a second conductive layer comprising a region in contact with an upper surface of the first oxide semiconductor layer;
a second insulating layer over the first oxide semiconductor layer and the second conductive layer; and
a third conductive layer electrically connected to the second conductive layer, the third conductive layer comprising a region over the second insulating layer; and
a connecting portion comprising:
a fourth conductive layer comprising a region in contact with the insulating surface, the fourth conductive layer comprising the same material as the first conductive layer;
the first insulating layer comprising a region in contact with an upper surface of the fourth conductive layer;
a second oxide semiconductor layer comprising a region in contact with the upper surface of the first insulating layer; and
a fifth conductive layer over the second oxide semiconductor layer, the fifth conductive layer comprising the same material as the third conductive layer,
wherein the first conductive layer is configured to serve as a gate electrode of the transistor,
wherein the second conductive layer is configured to serve as one of a source electrode and a drain electrode of the transistor,
wherein each of the first conductive layer and the fourth conductive layer comprises a stacked structure comprising a titanium layer and a copper layer over the titanium layer,
wherein the second conductive layer comprises a conductive metal oxide,
wherein the first insulating layer and the second oxide semiconductor layer comprise a contact hole, and
wherein the fifth conductive layer is electrically connected to the fourth conductive layer through the contact hole.
7. The display device according to claim 6 , wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises indium, gallium, zinc, and oxygen.
8. The display device according to claim 6 , further comprising:
a liquid crystal material over the third conductive layer.
9. The display device according to claim 6 , wherein the second conductive layer overlaps with the first conductive layer.
10. The display device according to claim 6 , wherein the channel formation region comprises crystals with c-axis alignment.
11. A display device comprising:
a pixel portion comprising:
a first conductive layer comprising a region in contact with an insulating surface;
a first insulating layer comprising a region in contact with an upper surface of the first conductive layer;
a first oxide semiconductor layer comprising a region in contact with an upper surface of the first insulating layer, the first oxide semiconductor layer comprising a channel formation region of a transistor;
a second conductive layer comprising a region in contact with an upper surface of the first oxide semiconductor layer;
a second insulating layer over the first oxide semiconductor layer and the second conductive layer; and
a third conductive layer electrically connected to the second conductive layer, the third conductive layer comprising a region over the second insulating layer; and
a connecting portion comprising:
a fourth conductive layer comprising a region in contact with the insulating surface, the fourth conductive layer comprising the same material as the first conductive layer;
the first insulating layer comprising a region in contact with an upper surface of the fourth conductive layer;
a second oxide semiconductor layer comprising a region in contact with the upper surface of the first insulating layer; and
a fifth conductive layer over the second oxide semiconductor layer, the fifth conductive layer comprising the same material as the third conductive layer,
wherein the first conductive layer is configured to serve as a gate electrode of the transistor,
wherein the second conductive layer is configured to serve as one of a source electrode and a drain electrode of the transistor,
wherein each of the first conductive layer and the fourth conductive layer comprises a stacked structure comprising a copper layer,
wherein the first insulating layer and the second oxide semiconductor layer comprise a contact hole, and
wherein the fifth conductive layer is electrically connected to the fourth conductive layer through the contact hole.
12. The display device according to claim 11 , wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises indium, gallium, zinc, and oxygen.
13. The display device according to claim 11 , further comprising:
a liquid crystal material over the third conductive layer.
14. The display device according to claim 11 , wherein the second conductive layer overlaps with the first conductive layer.
15. The display device according to claim 11 , wherein the channel formation region comprises crystals with c-axis alignment.