Semiconductor device

1. A semiconductor device comprising:

a first barrier layer;

a second barrier layer;

a third barrier layer;

a transistor comprising an oxide;

an insulator comprising an oxygen-excess region; and

a conductor,

wherein the insulator and the oxide are between the first barrier layer and the second barrier layer,

wherein the third barrier layer and the conductor are in an opening of the first barrier layer and an opening of the insulator,

wherein the conductor is not in contact with the insulator, and

wherein the third barrier layer is an insulating layer.

2. The semiconductor device according to claim 1 , wherein a side surface of the opening of the first barrier layer and a side surface of an opening of the second barrier layer are in contact with the third barrier layer, so that the transistor and the insulator are sealed by the first barrier layer, the second barrier layer, and the third barrier layer.

3. The semiconductor device according to claim 1 , wherein an amount of hydrogen released from components below the first barrier layer, the second barrier layer, or the third barrier layer is less than or equal to 5.0×10 14 /cm 2 when measured by TDS at a temperature lower than or equal to 400° C.

4. The semiconductor device according to claim 1 , further comprising:

a second insulator having an opening; and

a third insulator having an opening,

wherein the second insulator is over the second barrier layer,

wherein the third insulator is below the first barrier layer, and

wherein a side surface of the opening of the second insulator and a side surface of the opening of the third insulator each have a region covered by the third barrier layer.

5. The semiconductor device according to claim 1 , wherein the first barrier layer serves as a gate insulating film of the transistor.

6. A semiconductor device comprising:

a first barrier layer;

a second barrier layer;

a third barrier layer;

a transistor comprising an oxide;

an insulator comprising an oxygen-excess region; and

a conductor electrically connected to the transistor,

wherein the insulator and the oxide are between the first barrier layer and the second barrier layer,

wherein the conductor is in an opening of the first barrier layer and an opening of the insulator,

wherein the third barrier layer is between the conductor and the insulator,

wherein the third barrier layer is between the conductor and the first barrier layer, and

wherein the third barrier layer is an insulating layer.

7. The semiconductor device according to claim 6 , wherein a side surface of the opening of the first barrier layer and a side surface of an opening of the second barrier layer are in contact with the third barrier layer, so that the transistor and the insulator are sealed by the first barrier layer, the second barrier layer, and the third barrier layer.

8. The semiconductor device according to claim 6 , wherein an amount of hydrogen released from components below the first barrier layer, the second barrier layer, or the third barrier layer is less than or equal to 5.0×10 14 /cm 2 when measured by TDS at a temperature lower than or equal to 400° C.

9. The semiconductor device according to claim 6 , further comprising:

a second insulator having an opening; and

a third insulator having an opening,

wherein the second insulator is over the second barrier layer,

wherein the third insulator is below the first barrier layer, and

wherein a side surface of the opening of the second insulator and a side surface of the opening of the third insulator each have a region covered by the third barrier layer.

10. The semiconductor device according to claim 6 , wherein the first barrier layer serves as a gate insulating film of the transistor.

11. A semiconductor device comprising:

a first barrier layer;

a second barrier layer;

a third barrier layer;

a transistor comprising an oxide;

an insulator comprising an oxygen-excess region;

a first conductor; and

a second conductor,

wherein the second conductor is electrically connected to the transistor,

wherein the insulator and the oxide are between the first barrier layer and the second barrier layer,

wherein the first conductor is in an opening of the first barrier layer, an opening of the second barrier layer, and an opening of the insulator,

wherein the third barrier layer is between the first conductor and each of the first barrier layer, the second barrier layer, and the insulator,

wherein the second conductor is in the opening of the first barrier layer and the opening of the insulator, and

wherein the third barrier layer is between the second conductor and each of the first barrier layer and the insulator.

12. The semiconductor device according to claim 11 , wherein a side surface of the opening of the first barrier layer and a side surface of the opening of the second barrier layer are in contact with the third barrier layer, so that the transistor and the insulator are sealed by the first barrier layer, the second barrier layer, and the third barrier layer.

13. The semiconductor device according to claim 11 , wherein an amount of hydrogen released from components below the first barrier layer, the second barrier layer, or the third barrier layer is less than or equal to 5.0×10 14 /cm 2 when measured by TDS at a temperature lower than or equal to 400° C.

14. The semiconductor device according to claim 11 , further comprising:

a second insulator having an opening; and

a third insulator having an opening,

wherein the second insulator is over the second barrier layer,

wherein the third insulator is below the first barrier layer, and

wherein a side surface of the opening of the second insulator and a side surface of the opening of the third insulator each have a region covered by the third barrier layer.

15. The semiconductor device according to claim 11 , wherein the first barrier layer serves as a gate insulating film of the transistor.