Semiconductor device
An object of one embodiment of the present invention is to provide a semiconductor device with a novel structure in which stored data can be stored even when power is not supplied in a data storing time and there is no limitation on the number of times of writing. The semiconductor device includes a first transistor which includes a first channel formation region using a semiconductor material other than an oxide semiconductor, a second transistor which includes a second channel formation region using an oxide semiconductor material, and a capacitor. One of a second source electrode and a second drain electrode of the second transistor is electrically connected to one electrode of the capacitor.
1. A semiconductor device comprising:
a driver circuit comprising a second transistor;
an insulating layer over the second transistor; and
a memory cell over the insulating layer, the memory cell comprising:
a first transistor, a channel formation region of the first transistor comprising a first oxide semiconductor layer; and
a capacitor, one electrode of the capacitor electrically connected to one of a source and a drain of the first transistor.
2. The semiconductor device according to claim 1 , wherein the first oxide semiconductor layer comprises indium, gallium, and zinc.
3. The semiconductor device according to claim 1 , wherein the first oxide semiconductor layer comprises a crystal region.
4. The semiconductor device according to claim 1 ,
wherein a gate of the first transistor is electrically connected to a word line,
wherein the other of the source and the drain of the first transistor is electrically connected to a bit line, and
wherein the other electrode of the capacitor is electrically connected to a capacitor line.
5. The semiconductor device according to claim 1 , wherein an off-state current per micrometer of a channel width of the first transistor is 100 zA/μm or less at room temperature.
6. The semiconductor device according to claim 1 , wherein a channel formation region of the second transistor comprises a semiconductor material.
7. An electronic device comprising the semiconductor device according to claim 1 .
8. A semiconductor device comprising:
a driver circuit comprising a second transistor;
an insulating layer over the second transistor; and
a memory cell over the insulating layer, the memory cell comprising:
a first transistor, a channel formation region of the first transistor comprising a first oxide semiconductor layer; and
a capacitor comprising a second oxide semiconductor layer, one electrode of the capacitor electrically connected to one of a source and a drain of the first transistor.
9. The semiconductor device according to claim 8 , wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises indium, gallium, and zinc.
10. The semiconductor device according to claim 8 , wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises a crystal region.
11. The semiconductor device according to claim 8 ,
wherein a gate of the first transistor is electrically connected to a word line,
wherein the other of the source and the drain of the first transistor is electrically connected to a bit line, and
wherein the other electrode of the capacitor is electrically connected to a capacitor line.
12. The semiconductor device according to claim 8 , wherein an off-state current per micrometer of a channel width of the first transistor is 100 zA/μm or less at room temperature.
13. The semiconductor device according to claim 8 , wherein a channel formation region of the second transistor comprises a semiconductor material.
14. An electronic device comprising the semiconductor device according to claim 8 .
15. The semiconductor device according to claim 1 , wherein a channel formation region of the second transistor comprises silicon.
16. The semiconductor device according to claim 1 ,
wherein a gate of the first transistor is electrically connected to a word line,
wherein the other of the source and the drain of the first transistor is electrically connected to a bit line, and
wherein the other electrode of the capacitor is electrically connected to a capacitor line.
17. The semiconductor device according to claim 8 , wherein a channel formation region of the second transistor comprises silicon.
18. The semiconductor device according to claim 8 ,
wherein a gate of the first transistor is electrically connected to a word line,
wherein the other of the source and the drain of the first transistor is electrically connected to a bit line, and
wherein the other electrode of the capacitor is electrically connected to a capacitor line.