SEMICONDUCTOR DEVICE

• US 20110121887A1
• Filed: 11/16/2010
• Published: 05/26/2011
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kato, Kiyoshi, Koyama, Jun
• Granted Patent: US 8,467,825 B2
• Time in Patent Office: Days
• US Class Current: 327/534
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07773 Antenna details antennas for wireless devices, e.g. RFID tags, in general H01Q1/22
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/1033 with insulated gate, e.g. characterised by the length, the width, the geometric contour or the doping structure with channel and gate aligned in the lengthwise direction H01L29/42376; with buried channel H01L29/7838
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: Y02D 30/70 in wireless communication networks
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An object is to achieve low power consumption and a long lifetime of a semiconductor device having a wireless communication function. The object can be achieved in such a manner that a battery serving as a power supply source and a specific circuit are electrically connected to each other through a transistor in which a channel formation region is formed using an oxide semiconductor. The hydrogen concentration of the oxide semiconductor is lower than or equal to 5×10¹⁹ (atoms/cm³). Therefore, leakage current of the transistor can be reduced. As a result, power consumption of the semiconductor device in a standby state can be reduced. Further, the semiconductor device can have a long lifetime.

Claims

1. A semiconductor device comprising:

an antenna;

a battery supplying power supply voltage;

a demodulation circuit connected to the antenna;

a power control circuit connected to the demodulation circuit; and

a signal processing portion connected to the demodulation circuit, the power control circuit, and the battery,

wherein the signal processing portion comprises a transistor, and

wherein a channel formation region of the transistor comprises an oxide semiconductor with a hydrogen concentration of lower than or equal to 5×

10¹⁹ atoms/cm³.

2. The semiconductor device according to claim 1, further comprising a functional circuit connected to the battery through the transistor.

3. The semiconductor device according to claim 1, wherein the signal processing portion operates with the use of a signal input from the demodulation circuit and the power supply voltage supplied from the battery.

4. The semiconductor device according to claim 1, wherein the power control circuit is controlled by a signal input from the demodulation circuit.

5. The semiconductor device according to claim 1, wherein switching of the transistor is controlled by a signal input from the power control circuit.

6. The semiconductor device according to claim 1,

wherein the battery is a secondary battery, and

wherein the semiconductor device further comprises:

a rectifier circuit connected to the antenna;

a charge circuit connected to the secondary battery and the rectifier circuit; and

a stabilizing power supply circuit connected to the secondary battery.

7. The semiconductor device according to claim 1,

wherein the signal processing portion comprises a logic gate, and

wherein electrical connection between the logic gate and the battery is controlled by the transistor.

8. The semiconductor device according to claim 7,

wherein the logic gate comprises an n-channel transistor, and

wherein a channel formation region of the n-channel transistor comprises the oxide semiconductor.

9. The semiconductor device according to claim 7,

wherein the logic gate comprises a p-channel transistor and an n-channel transistor,

wherein a channel formation region of the p-channel transistor comprises a semiconductor including silicon as its main component, and

wherein a channel formation region of the n-channel transistor comprises the semiconductor including silicon as its main component or the oxide semiconductor.

10. A semiconductor device comprising:

an antenna;

a battery supplying power supply voltage;

a timer regularly outputting a signal;

a power control circuit connected to the timer; and

a signal processing portion connected to the timer, the power control circuit, and the battery,

wherein the signal processing portion comprises a transistor, and

wherein a channel formation region of the transistor comprises an oxide semiconductor with a hydrogen concentration of lower than or equal to 5×

10¹⁹ atoms/cm³.

11. The semiconductor device according to claim 10, further comprising a functional circuit connected to the battery through the transistor.

12. The semiconductor device according to claim 10, wherein the signal processing portion operates with the use of a signal input from the timer and the power supply voltage supplied from the battery.

13. The semiconductor device according to claim 10, wherein the power control circuit is controlled by a signal input from the timer.

14. The semiconductor device according to claim 10, wherein switching of the transistor is controlled by a signal input from the power control circuit.

15. The semiconductor device according to claim 10,

wherein the battery is a secondary battery, and

wherein the semiconductor device further comprises:

a rectifier circuit connected to the antenna;

a charge circuit connected to the secondary battery and the rectifier circuit; and

a stabilizing power supply circuit connected to the secondary battery.

16. The semiconductor device according to claim 10,

wherein the signal processing portion comprises a logic gate, and

wherein electrical connection between the logic gate and the battery is controlled by the transistor.

17. The semiconductor device according to claim 16,

wherein the logic gate comprises an n-channel transistor, and

wherein a channel formation region of the n-channel transistor comprises the oxide semiconductor.

18. The semiconductor device according to claim 16,

wherein the logic gate comprises a p-channel transistor and an n-channel transistor,

wherein a channel formation region of the p-channel transistor comprises a semiconductor including silicon as its main component, and

wherein a channel formation region of the n-channel transistor comprises the semiconductor including silicon as its main component or the oxide semiconductor.