Nonvolatile memory circuit with an oxide semiconductor transistor for reducing power consumption and electronic device

• US 8,705,292 B2
• Filed: 05/08/2012
• Issued: 04/22/2014
• Est. Priority Date: 05/13/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fujita, Masashi
• Primary Examiner(s): Tran, Andrew Q
• Application Number:
  US13/466,842
• Publication Number:
  US 20120287702A1
• Time in Patent Office: 714 Days
• Field of Search: 365/188, 365/174, 365/227, 365/228, 365/226
• US Class Current: 365/188
• CPC Class Codes: G11C 11/403 with charge regeneration common to a multiplicity of memory cells, i.e. external refresh
• CPC Class Codes: G11C 16/0433 comprising cells containing a single floating gate transistor and one or more separate select transistors

Abstract

To provide a nonvolatile memory circuit having a novel structure. A first memory circuit, a second memory circuit, a first switch, a second switch, and a phase inverter circuit are included. The first memory circuit includes a first transistor formed using an oxide semiconductor film, a second transistor, a third transistor, and a capacitor. The first transistor formed using an oxide semiconductor film and the capacitor are used to form the nonvolatile memory circuit. Reductions in number of power supply lines and signal lines which are connected to the memory circuit and transistors used in the memory circuit allow a reduction in circuit scale of the nonvolatile memory circuit.

Claims

1. A memory circuit comprising:

a first memory circuit;

a second memory circuit;

a first switch;

a second switch; and

a phase inverter circuit,

wherein the first memory circuit comprises a first transistor, a second transistor, a third transistor, and a capacitor,

wherein the first transistor comprises an oxide semiconductor film,

wherein one of a source and a drain of the first transistor is connected to a first signal line, and the other of the source and the drain of the first transistor is connected to one electrode of the capacitor and a gate of the second transistor,

wherein the other electrode of the capacitor is grounded,

wherein a gate of the first transistor is connected to a second signal line,

wherein an input terminal of the phase inverter circuit is connected to the second signal line, and an output terminal of the phase inverter circuit is connected to an input terminal of the first switch,

wherein a first terminal of the phase inverter circuit is connected to a power supply line, and a second terminal of the phase inverter circuit is grounded,

wherein a first terminal of the first switch is connected to the power supply line, a second terminal of the first switch is connected to one of a source and a drain of the second transistor, and the other of the source and the drain of the second transistor is grounded,

wherein a gate of the third transistor is connected to a gate of the second transistor, one of a source and a drain of the third transistor is connected to the power supply line, and the other of the source and the drain of the third transistor is connected to an output terminal of the first switch,

wherein a first terminal of the second switch is connected to the output terminal of the phase inverter circuit, and a second terminal of the second switch is connected to the second signal line, and

wherein the output terminal of the first switch is connected to the second memory circuit through the second switch.

2. The memory circuit according to claim 1,

wherein the first transistor comprises an oxide semiconductor material containing In, Ga, and Zn.

3. The memory circuit according to claim 1,

wherein the first transistor comprises an oxide semiconductor material containing In, Sn, and Zn.

4. An electronic device comprising:

the memory circuit according to claim 1.

5. A memory circuit comprising:

a first memory circuit;

a second memory circuit;

a first switch;

a second switch; and

a phase inverter circuit,

wherein the first memory circuit comprises a first transistor, a capacitor, a second transistor, and a third transistor,

wherein the first switch comprises a fourth transistor and a fifth transistor,

wherein the first transistor comprises an oxide semiconductor,

wherein one of a source and a drain of the first transistor is connected to a first signal line, and the other of the source and the drain of the first transistor is connected to one electrode of the capacitor and a gate of the second transistor,

wherein the other electrode of the capacitor is grounded,

wherein a gate of the first transistor is connected to a second signal line,

wherein an input terminal of the phase inverter circuit is connected to the second signal line, and an output terminal of the phase inverter circuit is connected to a gate of the fourth transistor and a gate of the fifth transistor,

wherein a first terminal of the phase inverter circuit is connected to a power supply line, and a second terminal of the phase inverter circuit is grounded,

wherein one of a source and a drain of the fourth transistor is connected to the power supply line, the other of the source and the drain of the fourth transistor is connected to one of a source and a drain of the fifth transistor, the other of the source and the drain of the fifth transistor is connected to one of a source and a drain of the second transistor, and the other of the source and the drain of the second transistor is grounded,

wherein a gate of the third transistor is connected to a gate of the second transistor, one of a source and a drain of the third transistor is connected to the power supply line, and the other of the source and the drain of the third transistor is connected to the other of the source and the drain of the fourth transistor and the one of the source and the drain of the fifth transistor,

wherein a first terminal of the second switch is connected to the output terminal of the phase inverter circuit, and a second terminal of the second switch is connected to the second signal line, and

wherein the other of the source and the drain of the fourth transistor and the one of the source and the drain of the fifth transistor are connected to the second memory circuit through the second switch.

6. The memory circuit according to claim 5,

wherein the first transistor comprises an oxide semiconductor material containing In, Ga, and Zn.

7. The memory circuit according to claim 5,

wherein the first transistor comprises an oxide semiconductor material containing In, Sn, and Zn.

8. An electronic device comprising:

the memory circuit according to claim 5.

9. A memory circuit comprising:

a first transistor comprising an oxide semiconductor, wherein one of a source and a drain of the first transistor is electrically connected to a first signal line, and a gate of the first transistor is electrically connected to a second signal line;

a second transistor, wherein a gate of the second transistor is electrically connected to the other of the source and the drain of the first transistor, and one of a source and a drain of the second transistor is electrically connected to a first power supply line;

a third transistor, wherein a gate of the third transistor is electrically connected to the other of the source and the drain of the first transistor, and one of a source and a drain of the third transistor is electrically connected to a second power supply line;

a fourth transistor, wherein one of a source and a drain of the fourth transistor is electrically connected to the second power supply line;

a fifth transistor, wherein a gate of the fifth transistor is electrically connected to a gate of the fourth transistor, one of a source and a drain of the fifth transistor is electrically connected to the other of the source and the drain of the third transistor and the other of the source and the drain of the fourth transistor, and the other of the source and the drain of the fifth transistor is electrically connected to the other of the source and the drain of the second transistor; and

a capacitor, wherein one electrode of the capacitor is electrically connected to the other of the source and the drain of the first transistor, and the other electrode of the capacitor is electrically connected to the first power supply line.

10. The memory circuit according to claim 9,

wherein the first transistor comprises an oxide semiconductor material containing In, Ga, and Zn.

11. The memory circuit according to claim 9,

wherein the first transistor comprises an oxide semiconductor material containing In, Sn, and Zn.

12. The memory circuit according to claim 9, further comprising a switch and a memory circuit electrically connected to the other of the source and the drain of the third transistor through the switch.

13. The memory circuit according to claim 9, further comprising a phase inverter circuit electrically connected to the gate of the fourth transistor and the gate of the fifth transistor.

14. The memory circuit according to claim 9,

wherein the second transistor and the fourth transistor are n-channel transistors, and

wherein the third transistor and the fifth transistor are p-channel transistors.

15. An electronic device comprising:

the memory circuit according to claim 9.