Semiconductor device and method for manufacturing the same
An object of the present invention is to prevent the deterioration of a TFT (thin film transistor). The deterioration of the TFT by a BT test is prevented by forming a silicon oxide nitride film between the semiconductor layer of the TFT and a substrate, wherein the silicon oxide nitride film ranges from 0.3 to 1.6 in a ratio of the concentration of N to the concentration of Si.
1. A semiconductor device comprising:
a first insulating layer comprising silicon, nitrogen, and oxygen over a substrate;
a second insulating layer comprising silicon, nitrogen, and oxygen over the first insulating layer;
a polycrystalline semiconductor film over the second insulating layer, the polycrystalline semiconductor film including a channel forming region;
a planarization layer over the polycrystalline semiconductor film, and
a pixel electrode over the planarization layer, wherein the pixel electrode is electrically in contact with the polycrystalline semiconductor film,
wherein a concentration ratio of nitrogen to silicon of the first insulating layer ranges from 0.3 to 1.6, and
wherein a concentration of nitrogen of the first insulating layer is higher than a concentration of nitrogen of the second insulating layer.
2. The semiconductor device according to claim 1 , wherein a concentration ratio of oxygen to silicon of the first insulating layer ranges from 0.1 to 1.7.
3. The semiconductor device according to claim 1 , wherein the concentration of nitrogen of the first insulating layer is higher than 2×10 20 atoms/cm 3 .
4. The semiconductor device according to claim 1 , wherein the substrate is a glass substrate.
5. The semiconductor device according to claim 1 , wherein the planarization layer includes a resin material.
6. The semiconductor device according to claim 1 , wherein the semiconductor device is incorporated into an electronic device selected from the group consisting of a personal computer, a video camera, a goggle type display, a player using a recording medium, a digital camera, a projector, a cellular phone, a digital book and a display.
7. The semiconductor device according to claim 1 , further comprising a liquid crystal layer interposed between the substrate and a second substrate.
8. The semiconductor device according to claim 1 , further comprising a light-emitting layer over the pixel electrode.
9. A semiconductor device comprising:
an insulating layer comprising silicon, nitrogen, and oxygen over a substrate;
a polycrystalline semiconductor film over the insulating layer, wherein the polycrystalline semiconductor film includes a channel forming region;
a planarization layer over the polycrystalline semiconductor film, and
a pixel electrode over the planarization layer, wherein the pixel electrode is electrically in contact with the polycrystalline semiconductor film,
wherein a concentration ratio of oxygen to silicon of the insulating layer ranges from 0.1 to 1.7, and
wherein a concentration ratio of nitrogen to silicon of the insulating layer ranges from 0.3 to 1.6.
10. The semiconductor device according to claim 9 , wherein a concentration of nitrogen of the insulating layer is higher than 2×10 20 atoms/cm 3 .
11. The semiconductor device according to claim 9 , wherein the substrate is a glass substrate.
12. The semiconductor device according to claim 9 , wherein the planarization layer includes a resin material.
13. The semiconductor device according to claim 9 , wherein the semiconductor device is incorporated into an electronic device selected from the group consisting of a personal computer, a video camera, a goggle type display, a player using a recording medium, a digital camera, a projector, a cellular phone, a digital book and a display.
14. The semiconductor device according to claim 9 , further comprising a liquid crystal layer interposed between the substrate and a second substrate.
15. The semiconductor device according to claim 9 , further comprising a light-emitting layer over the pixel electrode.
16. The semiconductor device according to claim 9 , further comprising:
a second insulating layer comprising silicon, nitrogen, and oxygen over the insulating layer; and
a third insulating layer comprising silicon and oxygen over the second insulating layer,
wherein the polycrystalline semiconductor film is provided over the third insulating layer.
17. A semiconductor device comprising:
an insulating layer comprising silicon, nitrogen, and oxygen over a substrate;
a polycrystalline semiconductor film formed over and in contact with the insulating layer, wherein the polycrystalline semiconductor film includes a channel forming region;
a gate insulating layer over the polycrystalline semiconductor film;
a gate electrode over the channel forming region with the gate insulating layer therebetween;
a planarization layer over the gate electrode, and
a pixel electrode over the planarization layer, wherein the pixel electrode is electrically in contact with the polycrystalline semiconductor film,
wherein a concentration ratio of nitrogen to silicon of the insulating layer ranges from 0.3 to 1.6.
18. The semiconductor device according to claim 17 , wherein a concentration ratio of oxygen to silicon of the insulating layer ranges from 0.1 to 1.7.
19. The semiconductor device according to claim 17 , wherein a concentration of nitrogen of the insulating layer is higher than 2×10 20 atoms/cm 3 .
20. The semiconductor device according to claim 17 , wherein the substrate is a glass substrate.
21. The semiconductor device according to claim 17 , wherein the planarization layer includes a resin material.
22. The semiconductor device according to claim 17 , wherein the semiconductor device is incorporated into an electronic device selected from the group consisting of a personal computer, a video camera, a goggle type display, a player using a recording medium, a digital camera, a projector, a cellular phone, a digital book and a display.
23. The semiconductor device according to claim 17 , further comprising a liquid crystal layer interposed between the substrate and a second substrate.
24. The semiconductor device according to claim 17 , further comprising a light-emitting layer over the pixel electrode.