Semiconductor device and method for manufacturing semiconductor device
A semiconductor device with a large storage capacity per unit area is provided. The semiconductor device includes a first insulator including a first opening, a first conductor that is over the first insulator and includes a second opening, a second insulator that is over the first insulator and includes a third opening, and an oxide penetrating the first opening, the second opening, and the third opening. The oxide includes a first region at least in the first opening, a second region at least in the second opening, and a third region at least in the third opening. The resistances of the first region and the third region are lower than the resistance of the second region.
1. A semiconductor device comprising:
a first conductor over a substrate;
a first insulator over the first conductor;
a second conductor over the first insulator; and
a third conductor, a second insulator, and an oxide which are embedded in a first opening in the first insulator and a second opening in the second conductor,
wherein the oxide comprises indium and zinc,
wherein the third conductor, the second insulator, and the oxide extend in a direction intersecting a top surface of the substrate,
wherein the oxide surrounds the third conductor with the second insulator provided therebetween, and
wherein a bottom surface of the oxide is in contact with a top surface of the first conductor.
2. The semiconductor device according to claim 1 , further comprising a third insulator between the oxide and the third conductor.
3. The semiconductor device according to claim 1 , wherein the oxide is in a columnar shape.
4. The semiconductor device according to claim 1 , wherein a width of the first opening is smaller than a width of the second opening.
5. The semiconductor device according to claim 1 , wherein the oxide further comprises a metal element selected from Al, Ga, Y, and Sn.
6. The semiconductor device according to claim 1 , wherein a top surface of the oxide is electrically connected to a fourth conductor.
7. The semiconductor device according to claim 6 ,
wherein the first conductor is one of a bit line and a source line, and
wherein the fourth conductor is the other of the bit line and the source line.
8. A semiconductor device comprising:
a first conductor over a substrate;
a first insulator over the first conductor;
a second conductor over the first insulator; and
a third conductor, a second insulator, and an oxide which are embedded in a first opening in the first insulator and a second opening in the second conductor,
wherein the oxide comprises indium and zinc,
wherein the third conductor, the second insulator, and the oxide extend in a direction intersecting a top surface of the substrate,
wherein the oxide surrounds the third conductor with the second insulator provided therebetween,
wherein a bottom surface of the oxide is in contact with a top surface of the first conductor,
wherein the oxide comprises a first region in the first opening and a second region in the second opening, and
wherein the resistance of the first region is lower than the resistance of the second region.
9. The semiconductor device according to claim 8 , further comprising a third insulator between the oxide and the third conductor.
10. The semiconductor device according to claim 8 , wherein the oxide is in a columnar shape.
11. The semiconductor device according to claim 8 , wherein a width of the first opening is smaller than a width of the second opening.
12. The semiconductor device according to claim 8 , wherein the oxide further comprises a metal element selected from Al, Ga, Y, and Sn.
13. The semiconductor device according to claim 8 , wherein a top surface of the oxide is electrically connected to a fourth conductor.
14. The semiconductor device according to claim 13 ,
wherein the first conductor is one of a bit line and a source line, and
wherein the fourth conductor is the other of the bit line and the source line.