Liquid crystal display device and electronic device using liquid crystal display device

• US 9,612,499 B2
• Filed: 03/17/2016
• Issued: 04/04/2017
• Est. Priority Date: 03/19/2015
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Kubota, Daisuke, Kubota, Yusuke
• Primary Examiner(s): Sandvik, Benjamin
• Assistant Examiner(s): ASSOUMAN, HERVE-LOUIS Y
• Application Number:
  US15/072,645
• Publication Number:
  US 20160274394A1
• Time in Patent Office: 383 Days
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/40 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 27/1229 with different crystal properties within a device or between different devices
• 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes

Abstract

A liquid crystal display device with an increased pixel aperture ratio is provided. A liquid crystal display device that displays an image with high contrast and high luminance is provided. The liquid crystal display device includes a first pixel electrode; a second pixel electrode; a transistor; a capacitor; a first insulating film; a second insulating film; and a third insulating film. The transistor includes a gate electrode; a gate insulating film; a first oxide semiconductor film; and a source electrode and a drain electrode. One of a pair of electrodes of the capacitor includes a second oxide semiconductor film. The first insulating film is provided over the first oxide semiconductor film. The second insulating film is provided over the second oxide semiconductor film such that the second oxide semiconductor film is sandwiched between the first insulating film and the second insulating film. The third insulating film overlaps with an end of the first pixel electrode. The second pixel electrode is provided over the third insulating film.

Claims

1. A semiconductor device comprising:

a first pixel electrode electrically connected to a first transistor;

a second pixel electrode;

the first transistor comprising;

a gate electrode;

a gate insulating film adjacent to the gate electrode; and

a first oxide semiconductor film which is adjacent to the gate insulating film and overlaps with the gate electrode;

a first insulating film over the first oxide semiconductor film;

a second oxide semiconductor film over the first insulating film;

a second insulating film over the second oxide semiconductor film; and

a third insulating film between the first pixel electrode and the second pixel electrode,

wherein a capacitor is formed between the first pixel electrode and the second oxide semiconductor film,

wherein the third insulating film overlaps with an end of the first pixel electrode, and

wherein the second pixel electrode is over the third insulating film.

2. The semiconductor device according to claim 1,

wherein the first insulating film comprises oxygen, and

wherein the second insulating film comprises hydrogen.

3. The semiconductor device according to claim 1, wherein the first pixel electrode is electrically connected to one of a source electrode and a drain electrode of the first transistor in an opening in the first insulating film and the second insulating film.

4. The semiconductor device according to claim 1, wherein resistivity of the second oxide semiconductor film is lower than resistivity of the first oxide semiconductor film.

5. The semiconductor device according to claim 1, wherein the second pixel electrode is electrically connected to a second transistor in a pixel adjacent to a pixel including the first transistor.

6. The semiconductor device according to claim 1, further comprising:

a first coloring film over the first pixel electrode; and

a second coloring film over the second pixel electrode.

7. The semiconductor device according to claim 1, wherein the semiconductor device is a liquid crystal display device.

8. A semiconductor device comprising:

a first pixel electrode electrically connected to a first transistor;

a second pixel electrode;

a conductive film which is electrically connected to and overlaps with the first pixel electrode;

the first transistor comprising;

a gate electrode;

a gate insulating film adjacent to the gate electrode; and

a first oxide semiconductor film which is adjacent to the gate insulating film and overlaps with the gate electrode;

a first insulating film over the first oxide semiconductor film;

a second oxide semiconductor film over the first insulating film;

a second insulating film over the second oxide semiconductor film; and

a third insulating film between the first pixel electrode and the second pixel electrode,

wherein a capacitor is formed between the first pixel electrode and the second oxide semiconductor film,

wherein the third insulating film overlaps with an end of the first pixel electrode, and

wherein the conductive film is over the third insulating film.

9. The semiconductor device according to claim 8,

wherein the first insulating film comprises oxygen, and

wherein the second insulating film comprises hydrogen.

10. The semiconductor device according to claim 8, wherein the first pixel electrode is electrically connected to one of a source electrode and a drain electrode of the first transistor in an opening in the first insulating film and the second insulating film.

11. The semiconductor device according to claim 8, wherein resistivity of the second oxide semiconductor film is lower than resistivity of the first oxide semiconductor film.

12. The semiconductor device according to claim 8, wherein the second pixel electrode is electrically connected to a second transistor in a pixel adjacent to a pixel including the first transistor.

13. The semiconductor device according to claim 8, further comprising:

a first coloring film over the first pixel electrode; and

a second coloring film over the second pixel electrode.

14. The semiconductor device according to claim 8, wherein the semiconductor device is a liquid crystal display device.

15. A semiconductor device comprising:

a first pixel electrode electrically connected to a first transistor;

a second pixel electrode;

the first transistor comprising;

a gate electrode;

a gate insulating film adjacent to the gate electrode; and

a first oxide semiconductor film which is adjacent to the gate insulating film and overlaps with the gate electrode;

a first insulating film over the first oxide semiconductor film;

a second oxide semiconductor film over the first insulating film;

a second insulating film over the second oxide semiconductor film; and

a third insulating film between the first pixel electrode and the second pixel electrode,

wherein a capacitor is formed between the first pixel electrode and a first part of the second oxide semiconductor film,

wherein a second part of the second oxide semiconductor film is a back gate electrode of the first transistor,

wherein the third insulating film overlaps with an end of the first pixel electrode, and

wherein the second pixel electrode is over the third insulating film.

16. The semiconductor device according to claim 15,

wherein the first insulating film comprises oxygen, and

wherein the second insulating film comprises hydrogen.

17. The semiconductor device according to claim 15, wherein the first pixel electrode is electrically connected to one of a source electrode and a drain electrode of the first transistor in an opening in the first insulating film and the second insulating film.

18. The semiconductor device according to claim 15, wherein resistivity of the second oxide semiconductor film is lower than resistivity of the first oxide semiconductor film.

19. The semiconductor device according to claim 15, wherein the second pixel electrode is electrically connected to a second transistor in a pixel adjacent to a pixel including the first transistor.

20. The semiconductor device according to claim 15, further comprising:

a first coloring film over the first pixel electrode; and

a second coloring film over the second pixel electrode.

21. The semiconductor device according to claim 15, wherein the semiconductor device is a liquid crystal display device.