Semiconductor circuit, method for driving the same, storage device, register circuit, display device, and electronic device

• US 9,024,317 B2
• Filed: 12/05/2011
• Issued: 05/05/2015
• Est. Priority Date: 12/24/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Endo, Masami, Ohshima, Kazuaki
• Primary Examiner(s): Sarkar, Asok K
• Assistant Examiner(s): Yemelyanov, Dmitriy
• Application Number:
  US13/310,824
• Publication Number:
  US 20120161139A1
• Time in Patent Office: 1,247 Days
• Field of Search: 257/59, 257/60, 257/E29.296, 257/E33.053
• US Class Current: 257/57
• CPC Class Codes: G09G 2300/043 Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2320/0214 with crosstalk due to leakage current of pixel switch in active matrix panels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A semiconductor circuit capable of controlling and holding the threshold voltage of a transistor at an optimal level and a driving method thereof are disclosed. A storage device, a display device, or an electronic device including the semiconductor circuit is also provided. The semiconductor circuit comprises a diode and a first capacitor provided in a node to which a transistor to be controlled is connected through its back gate. This structure allows the application of desired voltage to the back gate so that the threshold voltage of the transistor is controlled at an optimal level and can be held for a long time. A second capacitor connected in parallel with the diode is optionally provided so that the voltage of the node can be changed temporarily.

Claims

1. A circuit comprising:

a diode comprising a first electrode and a second electrode;

a first capacitor electrically connected to the second electrode of the diode;

a second capacitor comprising a first electrode and a second electrode; and

a transistor comprising a back gate,

wherein the first electrode of the diode is configured to be input with a signal,

wherein the first electrode of the diode is electrically connected to the first electrode of the second capacitor,

wherein the second electrode of the diode is electrically connected to the second electrode of the second capacitor to form a node, and

wherein the back gate is electrically connected to the node.

2. The circuit according to claim 1, wherein the transistor comprises an oxide semiconductor in a channel.

3. The circuit according to claim 1,

wherein the diode is a second transistor comprising the first electrode, the second electrode, and a gate,

wherein the first electrode of the second transistor is electrically connected to the first electrode of the second capacitor, and

wherein the second electrode of the second transistor is electrically connected to the gate, the back gate, and the second electrode of the second capacitor.

4. The circuit according to claim 3, wherein the second transistor further comprises a back gate electrically connected to the second electrode of the second transistor.

5. The circuit according to claim 3, wherein the second transistor comprises an oxide semiconductor in a channel.

6. An electronic device comprising the circuit according to claim 1.

7. A circuit comprising:

a control circuit comprising;

a diode comprising a first electrode and a second electrode;

a first capacitor electrically connected to the second electrode of the diode; and

a second capacitor comprising a first electrode and a second electrode; and

a pixel comprising;

a first transistor comprising a first electrode, a second electrode, a gate, and a back gate;

a third capacitor electrically connected to the second electrode of the first transistor; and

a display element electrically connected to the second electrode of the first transistor,

wherein the first electrode of the diode is configured to be input with a signal,

wherein the first electrode of the diode is electrically connected to the first electrode of the second capacitor,

wherein the second electrode of the diode is electrically connected to the second electrode of the second capacitor to form a node, and

wherein the back gate is electrically connected to the node.

8. The circuit according to claim 7, wherein the first transistor comprises an oxide semiconductor in a channel.

9. The circuit according to claim 7,

wherein the diode is a second transistor comprising the first electrode, the second electrode, and a gate,

wherein the first electrode of the second transistor is electrically connected to the first electrode of the second capacitor, and

wherein the second electrode of the second transistor is electrically connected to the gate of the second transistor, the back gate of the first transistor, and the second electrode of the second capacitor.

10. The circuit according to claim 9,

wherein the second transistor further comprises a back gate, and

wherein the back gate of the second transistor is electrically connected to the second electrode of the second transistor.

11. The circuit according to claim 9, wherein the second transistor comprises an oxide semiconductor in a channel.

12. An electronic device comprising the circuit according to claim 9.