Semiconductor device
View Patent ↗It is an object to provide a semiconductor device in which power consumption can be reduced. It is another object to provide a highly reliable semiconductor device using a programming cell, such as a programmable logic device (PLD). In accordance with a change in a configuration of connections between basic blocks, power supply voltage furnishing to the basic blocks is changed. That is, when the structure of connections between the basic blocks is such that a basic block does not contribute to a circuit, the supply of the power supply voltage to this basic block is stopped. Further, the supply of the power supply voltage to the basic blocks is controlled using a programming cell formed using a field effect transistor whose channel formation region is formed using an oxide semiconductor, the field effect transistor having extremely low off-state current or extremely low leakage current.
1. A semiconductor device comprising:
basic blocks each comprising a logic circuit;
a node configured to be applied with a power supply potential; and
programming cells each comprising:
a first transistor comprising a gate electrode, a source electrode and a drain electrode; and
a second transistor comprising a gate electrode, a source electrode and a drain electrode, one of the source electrode and the drain electrode of the second transistor being configured to be at a same potential as the gate electrode of the first transistor,
wherein the node is connected to one of the basic blocks through the source electrode and the drain electrode of the first transistor of a corresponding one of the programming cells, and
wherein the second transistors each comprise a channel formation region comprising an oxide semiconductor layer.
2. The semiconductor device according to claim 1 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor.
3. The semiconductor device according to claim 1 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor; and
a capacitor comprising a first electrode and a second electrode, the first electrode being connected to the other of the source electrode and the drain electrode of the third transistor, and the second electrode being connected to each of the gate electrode of the third transistor and the gate electrode of the first transistor.
4. The semiconductor device according to claim 1 , wherein the oxide semiconductor layer comprises an In—Ga—Zn—O-based oxide semiconductor.
5. The semiconductor device according to claim 1 , wherein off-state current densities of the second transistors are lower than or equal to 100 zA/μm.
6. The semiconductor device according to claim 1 , wherein the first transistors and the second transistors are formed on a same substrate, the second transistors being formed over an insulating film that covers the first transistors.
7. A programmable logic device including the semiconductor device according to claim 1 .
8. A semiconductor device comprising:
basic blocks each comprising a logic circuit; and
programming cells each comprising:
a first transistor comprising a gate electrode, a source electrode and a drain electrode; and
a second transistor comprising a gate electrode, a source electrode and a drain electrode, one of the source electrode and the drain electrode of the second transistor being configured to be at a same potential as the gate electrode of the first transistor,
wherein a first one of the basic blocks is connected to a second one of the basic blocks through the source electrode and the drain electrode of one of the first transistors, and
wherein the second transistors each comprise a channel formation region comprising an oxide semiconductor layer.
9. The semiconductor device according to claim 8 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor.
10. The semiconductor device according to claim 8 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor; and
a capacitor comprising a first electrode and a second electrode, the first electrode being connected to the other of the source electrode and the drain electrode of the third transistor, and the second electrode being connected to each of the gate electrode of the third transistor and the gate electrode of the first transistor.
11. The semiconductor device according to claim 8 , wherein the oxide semiconductor layer comprises an In—Ga—Zn—O-based oxide semiconductor.
12. The semiconductor device according to claim 8 , wherein off-state current densities of the second transistors are lower than or equal to 100 zA/μm.
13. The semiconductor device according to claim 8 , wherein the first transistors and the second transistors are formed on a same substrate, the second transistors being formed over an insulating film that covers the first transistors.
14. A programmable logic device including the semiconductor device according to claim 8 .
15. A semiconductor device comprising:
basic blocks each comprising a logic circuit;
a wiring; and
programming cells each comprising:
a first transistor comprising a gate electrode, a source electrode and a drain electrode; and
a second transistor comprising a gate electrode, a source electrode and a drain electrode, one of the source electrode and the drain electrode of the second transistor being connected to the gate electrode of the first transistor,
wherein the wiring is connected to the basic blocks through the source electrodes and the drain electrodes of the first transistors, and
wherein the second transistors each comprise a channel formation region comprising an oxide semiconductor layer.
16. The semiconductor device according to claim 15 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor.
17. The semiconductor device according to claim 15 , further comprising in each programming cell:
a third transistor comprising a gate electrode, a source electrode and a drain electrode, the gate electrode of the third transistor being connected to the gate electrode of the first transistor, and one of the source electrode and the drain electrode of the third transistor being connected to the other of the source electrode and the drain electrode of the first transistor; and
a capacitor comprising a first electrode and a second electrode, the first electrode being connected to the other of the source electrode and the drain electrode of the third transistor, and the second electrode being connected to each of the gate electrode of the third transistor and the gate electrode of the first transistor.
18. The semiconductor device according to claim 15 , wherein the oxide semiconductor layer comprises an In—Ga—Zn—O-based oxide semiconductor.
19. The semiconductor device according to claim 15 , wherein off-state current density of the second transistor is lower than or equal to 100 zA/μm.
20. The semiconductor device according to claim 15 , wherein the first transistors and the second transistors are formed on a same substrate, the second transistors being formed over an insulating film that covers the first transistors.
21. A programmable logic device including the semiconductor device according to claim 15 .