Semiconductor device comprising oxygen blocking films
View Patent ↗A semiconductor device with favorable electrical characteristics is provided. The semiconductor device includes a first insulator, a first oxide over the first insulator, a second insulator provided between the first insulator and the first oxide, a second oxide in contact with the first insulator and in contact with a side surface of the first oxide, and a third insulator over the first insulator, the second oxide, and the first oxide. The third insulator includes a region in contact with a top surface of the first oxide. The second insulator and the third insulator include a material which is less likely to pass oxygen than the second oxide.
1. A semiconductor device comprising:
a first insulator;
a first oxide over the first insulator;
a first oxygen blocking film provided between the first insulator and the first oxide;
a second oxide in contact with the first insulator and in contact with a side surface of the first oxide; and
a second oxygen blocking film over the first insulator, the second oxide, and the first oxide,
wherein the second oxygen blocking film comprises a region in contact with a top surface of the first oxide, and
wherein the first oxygen blocking film and the second oxygen blocking film comprise a material which is less likely to pass oxygen than the second oxide.
2. The semiconductor device according to claim 1 ,
wherein the first oxide comprises indium, an element M, and zinc, and
wherein M is aluminum, gallium, yttrium, or tin.
3. The semiconductor device according to claim 1 , wherein the first oxide comprises a region functioning as a channel formation region.
4. The semiconductor device according to claim 1 , wherein the first oxide and the second oxide comprise the same material.
5. The semiconductor device according to claim 1 , wherein the second oxide has crystallinity and a c-axis of a crystal of the second oxide is in a direction substantially perpendicular to the side surface of the first oxide.
6. The semiconductor device according to claim 1 , wherein the second oxide is in contact with a side surface of the first oxygen blocking film and the second oxygen blocking film.
7. The semiconductor device according to claim 1 , wherein at least one of the first oxygen blocking film and the second oxygen blocking film comprises aluminum oxide.
8. A semiconductor device comprising:
a first insulator;
a first oxide over the first insulator;
a first oxygen blocking film provided between the first insulator and the first oxide;
a second oxide in contact with the first insulator and in contact with a side surface of the first oxide;
a first conductor and a second conductor provided over the first oxide and apart from each other;
a second oxygen blocking film over the first insulator, the second oxide, and the first oxide; and
a gate electrode over the second oxygen blocking film,
wherein the gate electrode comprises a region overlapping with the first oxide,
wherein the second oxygen blocking film comprises a region in contact with a top surface of the first oxide, a side surface of the first conductor, and a side surface of the second conductor, and
wherein the first oxygen blocking film and the second oxygen blocking film comprise a material which is less likely to pass oxygen than the second oxide.
9. The semiconductor device according to claim 8 , further comprising a second insulator,
wherein the second insulator is provided between the second oxygen blocking film and the gate electrode.
10. The semiconductor device according to claim 8 ,
wherein the first oxide comprises indium, an element M, and zinc, and
wherein M is aluminum, gallium, yttrium, or tin.
11. The semiconductor device according to claim 8 , wherein the first oxide comprises a region functioning as a channel formation region.
12. The semiconductor device according to claim 8 , wherein the first oxide and the second oxide comprise the same material.
13. The semiconductor device according to claim 8 , wherein the second oxide has crystallinity and a c-axis of a crystal of the second oxide is in a direction substantially perpendicular to the side surface of the first oxide.
14. The semiconductor device according to claim 8 , wherein the second oxide is in contact with a side surface of the first oxygen blocking film and the second oxygen blocking film.
15. The semiconductor device according to claim 8 , wherein at least one of the first oxygen blocking film and the second oxygen blocking film comprises aluminum oxide.
16. The semiconductor device according to claim 8 , wherein a top surface of the second oxygen blocking film and a top surface of the gate electrode are aligned with each other.