SEMICONDUCTOR DEVICE

• US 20140061636A1
• Filed: 08/27/2013
• Published: 03/06/2014
• Est. Priority Date: 08/28/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Miyake, Hiroyuki, Yamazaki, Shunpei
• Granted Patent: US 9,425,220 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• 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 2201/40 Arrangements for improving the aperture ratio
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

A semiconductor device having a high aperture ratio, including a capacitor with increased capacitance, and consuming low power is provided. The semiconductor device includes pixels defined by x (x is an integer of 2 or more) scan lines and y (y is an integer of 1 or more) signal lines, and each of the pixels includes a transistor, and a capacitor. The transistor includes a semiconductor film having a light-transmitting property. The capacitor includes a dielectric film between a pair of electrodes. In the capacitor between an (m−1)-th (m is an integer of 2 or more and x or less) scan line and an m-th scan line, a semiconductor film on the same surface as the semiconductor film having a light-transmitting property of the transistor serves as one of the pair of electrodes and is electrically connected to the (m−1)-th scan line.

Claims

1. A semiconductor device comprising:

a signal line;

a first scan line;

a second scan line;

a first transistor comprising a source, a drain, and a gate;

a second transistor comprising a source, a drain, and a gate;

a pixel electrode; and

a capacitor comprising an electrode and the pixel electrode over the electrode,

wherein one of the source and the drain of the first transistor is electrically connected to the pixel electrode,

wherein the first scan line is electrically connected to the gate of the first transistor,

wherein the signal line is electrically connected to the other of the source and the drain of the first transistor and one of the source and the drain of the second transistor,

wherein the second scan line is electrically connected to the gate of the second transistor and the electrode of the capacitor, and

wherein the electrode of the capacitor comprises an oxide film comprising indium and zinc.

2. The semiconductor device according to claim 1, wherein the first transistor comprises an oxide semiconductor film over the gate of the first transistor.

3. The semiconductor device according to claim 2, wherein the oxide semiconductor film comprises indium and zinc.

4. The semiconductor device according to claim 2, further comprising an insulating film over the oxide semiconductor film, wherein the source and the drain of the first transistor are over the insulating film.

5. The semiconductor device according to claim 2, wherein the electrode of the capacitor has higher conductivity than the oxide semiconductor film.

6. The semiconductor device according to claim 2, wherein the electrode of the capacitor and the oxide semiconductor film of the first transistor are provided on a same insulating surface.

7. The semiconductor device according to claim 1, comprising an insulating film over the first scan line and the second scan line,

wherein the source and the drain of the first transistor are over the insulating film,

wherein the insulating film comprises an opening, and

wherein the electrode of the capacitor is in contact with the second scan line in the opening of the insulating film.

8. The semiconductor device according to claim 1, comprising a nitride insulating film in contact with an upper surface of the electrode of the capacitor.

9. The semiconductor device according to claim 1, comprising a nitride insulating film in contact with a lower surface of the electrode of the capacitor.

10. The semiconductor device according to claim 1, wherein the electrode of the capacitor comprises an impurity including at least one selected from the group consisting of boron, nitrogen, fluorine, aluminum, phosphorus, arsenic, indium, tin, antimony, and a rare gas element.

11. The semiconductor device according to claim 1, further comprising a liquid crystal over the pixel electrode.

12. A semiconductor device comprising:

a substrate;

a first scan line and a second scan line over the substrate;

a first insulating film over the first scan line and the second scan line;

a first oxide film, a second oxide film, and a third oxide film each over the first insulating film;

a signal line over and electrically connected to the first oxide film and the third oxide film;

a conductive film over and electrically connected to the first oxide film;

a second insulating film over the signal line, the conductive film, and the second oxide film; and

a pixel electrode over the second insulating film and electrically connected to the conductive film,

wherein each of the first oxide film, the second oxide film, and the third oxide film comprises indium and zinc,

wherein the first oxide film overlaps with the first scan line,

wherein the second oxide film overlaps with the pixel electrode,

wherein the third oxide film overlaps with the second scan line, and

wherein the second oxide film is electrically connected to the second scan line.

13. The semiconductor device according to claim 12, wherein the second oxide film has higher conductivity than the first oxide film and the third oxide film.

14. The semiconductor device according to claim 12, wherein the first insulating film is a nitride film and in contact with the second oxide film.

15. The semiconductor device according to claim 12, wherein the second insulating film is a nitride film and in contact with the second oxide film.

16. The semiconductor device according to claim 12, wherein the second oxide film comprises an impurity including at least one selected from the group consisting of boron, nitrogen, fluorine, aluminum, phosphorus, arsenic, indium, tin, antimony, and a rare gas element.

17. The semiconductor device according to claim 12, wherein the first insulating film is an oxide film and in contact with the first oxide film and the third oxide film.

18. The semiconductor device according to claim 12, wherein the second insulating film is an oxide film and in contact with the first oxide film and the third oxide film.

19. The semiconductor device according to claim 12, further comprising a third insulating film between the second insulating film and the signal line,

wherein the second insulating film is in contact with the second oxide film.

20. The semiconductor device according to claim 12, further comprising a liquid crystal over the pixel electrode.