SEMICONDUCTOR DEVICE

• US 20140034954A1
• Filed: 08/02/2013
• Published: 02/06/2014
• Est. Priority Date: 08/03/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Miyake, Hiroyuki, Shishido, Hideaki, Koyama, Jun, Matsubayashi, Daisuke, Murayama, Keisuke
• Granted Patent: US 9,449,996 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136204 Arrangements to prevent high voltage or static electricity failures
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2201/40 Arrangements for improving the aperture ratio
• 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: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors

Abstract

To provide a semiconductor device including a capacitor whose charge capacity is increased without reducing the aperture ratio. The semiconductor device includes a transistor including a light-transmitting semiconductor film, a capacitor where a dielectric film is provided between a pair of electrodes, an insulating film provided over the light-transmitting semiconductor film, and a light-transmitting conductive film provided over the insulating film. In the capacitor, a metal oxide film containing at least indium (In) or zinc (Zn) and formed on the same surface as the light-transmitting semiconductor film in the transistor serves as one electrode, the light-transmitting conductive film serves as the other electrode, and the insulating film provided over the light-transmitting semiconductor film serves as the dielectric film.

Claims

1. A semiconductor device comprising:

a substrate;

a first insulating film over the substrate;

a second insulating film over the first insulating film;

a light-transmitting pixel electrode over the second insulating film;

a transistor comprising;

a gate electrode;

the first insulating film over the gate electrode; and

a semiconductor film over the first insulating film and overlapping the gate electrode, the semiconductor film being electrically connected to the pixel electrode; and

a capacitor comprising;

a light-transmitting film able to conduct electricity as a first capacitor electrode over part of the first insulating film;

the second insulating film as a capacitor dielectric film over the first capacitor electrode; and

the pixel electrode as a second capacitor electrode over the capacitor dielectric film.

2. The semiconductor device according to claim 1,

wherein the first insulating film is partly etched in a region between the first capacitor electrode and the second capacitor electrode.

3. The semiconductor device according to claim 1,

wherein the second insulating film is partly etched in a region between the first capacitor electrode and the second capacitor electrode.

4. The semiconductor device according to claim 1,

wherein the first capacitor electrode and the semiconductor film are formed from a same film.

5. The semiconductor device according to claim 1,

wherein the first capacitor electrode and the semiconductor film are formed from an oxide semiconductor film.

6. The semiconductor device according to claim 1,

wherein the first capacitor electrode and the semiconductor film are formed from an oxide semiconductor film, and

wherein the first capacitor electrode further contains a dopant at a concentration greater than 1×

10¹⁹ atoms/cm³ and less than or equal to 1×

10²² atoms/cm³.

7. The semiconductor device according to claim 1, further comprising an organic insulating film interposed between the second insulating film and the pixel electrode,

wherein the pixel electrode is in direct contact with the second insulating film through an opening in the organic insulating film.

8. The semiconductor device according to claim 1, further comprising a capacitor line formed from a same film as the gate electrode,

wherein the first capacitor electrode is connected to the capacitor line through a film formed from a same film as a source electrode or a drain electrode of the transistor.

9. The semiconductor device according to claim 1, further comprising a capacitor line,

wherein the light-transmitting film able to conduct electricity contains a semiconductor material, and

wherein the semiconductor device is configured so that, when used, a potential applied to the capacitor line is constantly lower than a potential to be supplied to the pixel electrode by a threshold voltage of the capacitor or more.

10. A display device comprising the semiconductor device according to claim 1.

11. An electronic device comprising the semiconductor device according to claim 1.

12. A semiconductor device comprising:

a substrate;

a first insulating film over the substrate;

a second insulating film over the first insulating film;

a light-transmitting pixel electrode over the second insulating film;

a transistor comprising;

a gate electrode;

the first insulating film over the gate electrode; and

a metal oxide semiconductor film over the first insulating film and overlapping the gate electrode, the metal oxide semiconductor film being electrically connected to the pixel electrode; and

a capacitor comprising;

a light-transmitting film able to conduct electricity as a first capacitor electrode over at least part of the first insulating film;

the second insulating film over the first capacitor electrode as a capacitor dielectric film; and

the pixel electrode as a second capacitor electrode over the capacitor dielectric film,

wherein the first capacitor electrode and the metal oxide semiconductor film are formed from a same film, and

wherein the first insulating film and the second insulating film comprise respectively a first oxide insulating film and a second oxide insulating film, each of the first oxide insulating film and the second oxide insulating film being in direct contact with the metal oxide semiconductor film.

13. The semiconductor device according to claim 12,

wherein the first insulating film comprises a nitride insulating film under the first oxide insulating film,

wherein the first capacitor electrode is in direct contact with the nitride insulating film.

14. The semiconductor device according to claim 12,

wherein the second insulating film comprises a nitride insulating film over the second oxide insulating film, and

wherein the first capacitor electrode is in direct contact with the nitride insulating film.

15. The semiconductor device according to claim 12,

wherein the first capacitor electrode contains a dopant at a concentration greater than 1×

10¹⁹ atoms/cm³ and less than or equal to 1×

10²² atoms/cm³.

16. The semiconductor device according to claim 12, further comprising an organic insulating film interposed between the second insulating film and the pixel electrode,

wherein the pixel electrode is in direct contact with the second insulating film through an opening in the organic insulating film.

17. The semiconductor device according to claim 12, further comprising a capacitor line formed from a same film as the gate electrode,

wherein the first capacitor electrode is connected to the capacitor line through a film formed from a same film as a source electrode or a drain electrode of the transistor.

18. The semiconductor device according to claim 12, further comprising a capacitor line,

wherein the semiconductor device is configured so that, when used, a potential applied to the capacitor line is constantly lower than a potential to be supplied to the pixel electrode by a threshold voltage of the capacitor or more.

19. A display device comprising the semiconductor device according to claim 12.

20. An electronic device comprising the semiconductor device according to claim 12.