SEMICONDUCTOR DEVICE, DISPLAY DEVICE, AND ELECTRONIC APPLIANCE

• US 20100156877A1
• Filed: 03/03/2010
• Published: 06/24/2010
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Granted Patent: US 8,981,443 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3241 the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission

Abstract

In case the size of the transistor is enlarged, power consumption of the transistor is increased. Thus, the present invention provides a display device capable of preventing a current from flowing to a display element in signal writing operation without varying potentials of power source lines for supplying a current to the display element per row. In setting a gate-source voltage of a transistor by applying a predetermined current to the transistor, a potential of a gate terminal of the transistor is adjusted so as to prevent a current from flowing to a load connected to a source terminal of the transistor. Therefore, a potential of a wire connected to the gate terminal of the transistor is differentiated from a potential of a wire connected to a drain terminal of the transistor.

Claims

1. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film over the transistor and the capacitor,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes ZnO.

2. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film over the transistor and the capacitor,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes a-InGaZnO.

3. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film over the transistor and the capacitor,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes at least two of In, Ga and Zn.

4. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the wiring overlaps an end of the insulating film, and wherein the semiconductor layer includes ZnO.

5. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the wiring overlaps an end of the insulating film, and

wherein the semiconductor layer includes a-InGaZnO.

6. A semiconductor device comprising:

a lightemitting element;

a transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the transistor is electrically connected to a pixel electrode of the lightemitting element via a wiring,

wherein an electrode of the capacitor is electrically connected to the pixel electrode of the lightemitting element,

wherein the wiring overlaps an end of the insulating film, and

wherein the semiconductor layer includes at least two of In, Ga and Zn.

7. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film over the first transistor, the second transistor and the capacitor,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes ZnO.

8. The semiconductor device according to claim 7, wherein the display element includes an electron ink.

9. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film over the first transistor, the second transistor and the capacitor,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes a-InGaZnO.

10. The semiconductor device according to claim 9, wherein the display element includes an electron ink.

11. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film over the first transistor, the second transistor and the capacitor,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the insulating film covers at least part of the wiring and is in contact with the semiconductor layer, and

wherein the semiconductor layer includes at least two of In, Ga and Zn.

12. The semiconductor device according to claim 11, wherein the display element includes an electron ink.

13. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the wiring overlaps an end of the insulating film, and

wherein the semiconductor layer includes ZnO.

14. The semiconductor device according to claim 13, wherein the display element includes an electron ink.

15. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the wiring overlaps an end of the insulating film, and

wherein the semiconductor layer includes a-InGaZnO.

16. The semiconductor device according to claim 15, wherein the display element includes an electron ink.

17. A semiconductor device comprising:

a display element;

a first transistor including a gate electrode, a gate insulating film over the gate electrode and a semiconductor layer over the gate insulating film;

a second transistor;

a capacitor; and

an insulating film on the semiconductor layer,

wherein one of a source and a drain of the first transistor is electrically connected to a pixel electrode of the display element via a wiring,

wherein one of a source and a drain of the second transistor is electrically connected to the pixel electrode of the display element,

wherein a first electrode of the capacitor is electrically connected to the pixel electrode of the display element,

wherein a second electrode of the capacitor is electrically connected to a gate electrode of the second transistor,

wherein the wiring overlaps an end of the insulating film, and

wherein the semiconductor layer includes at least two of In, Ga and Zn.

18. The semiconductor device according to claim 17, wherein the display element includes an electron ink.