Sequential circuit and semiconductor device

• US 9,494,830 B2
• Filed: 05/29/2014
• Issued: 11/15/2016
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Miyake, Hiroyuki, Toyotaka, Kouhei, Hayakawa, Masahiko, Matsubayashi, Daisuke, Matsuda, Shinpei
• Primary Examiner(s): Nguyen, Sang V
• Application Number:
  US14/290,263
• Publication Number:
  US 20140362324A1
• Time in Patent Office: 901 Days
• Field of Search: 349/47
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1343 Electrodes reflective electrodes G02F1/133553
• 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 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13685 Top gates
• 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

The following semiconductor device provides high reliability and a narrower frame width. The semiconductor device includes a driver circuit and a pixel portion. The driver circuit has a first transistor including a first gate and a second gate electrically connected to each other with a semiconductor film sandwiched therebetween, and a second transistor electrically connected to the first transistor. The pixel portion includes a third transistor, a liquid crystal element, and a capacitor. The liquid crystal element includes a first transparent conductive film electrically connected to the third transistor, a second conductive film, and a liquid crystal layer. The capacitor includes the first conductive film, a third transparent conductive film, and a nitride insulating film. The nitride insulating film is positioned between the first transparent conductive film and the third transparent conductive film, and positioned between the semiconductor film and the second gate of the first transistor.

Claims

1. A semiconductor device comprising:

a first insulating film comprising a nitride;

a driver circuit comprising;

a first transistor including a first gate, a second gate, a semiconductor film between the first gate and the second gate, a second insulating film, and a third insulating film comprising a nitride, each of the second insulating film and the third insulating film between the second gate and the semiconductor film; and

a second transistor; and

a pixel portion comprising;

a third transistor;

a liquid crystal element comprising;

a first transparent conductive film electrically connected to the third transistor;

a first conductive film over the first transparent conductive film; and

a liquid crystal layer between the first transparent conductive film and the first conductive film; and

a capacitor comprising;

a second transparent conductive film;

the first transparent conductive film over the second transparent conductive film; and

the third insulating film between the first transparent conductive film and the second transparent conductive film, the third insulating film is in contact with the second transparent conductive film,

wherein a first portion of the first insulating film comprises the second insulating film and the third insulating film over the second insulating film,

wherein a second portion of the first insulating film comprises the third insulating film in the capacitor,

wherein the first gate of the first transistor is electrically connected to the second gate of the first transistor,

wherein one of a source and a drain of the first transistor is configured to receive a first potential,

wherein one of a source and a drain of the second transistor is configured to receive a second potential,

wherein the second potential is lower than the first potential, and

wherein the other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor.

2. The semiconductor device according to claim 1,

wherein the one of the source and the drain of the first transistor is further configured to receive the second potential, and

wherein the one of the source and the drain of the first transistor is configured to receive the first potential and the second potential alternately.

3. The semiconductor device according to claim 1, wherein each of a first channel formation region of the first transistor, a second channel formation region of the second transistor and a third channel formation region of the third transistor comprises an oxide semiconductor film.

4. The semiconductor device according to claim 3, wherein the oxide semiconductor film comprises In, Zn and O.

5. The semiconductor device according to claim 1, wherein the first insulating film comprises a height difference between the first portion of the first insulating film and the second portion of the first insulating film.

6. The semiconductor device according to claim 1, wherein the second transparent conductive film comprises In, Zn and O.

7. The semiconductor device according to claim 3, wherein end portions of the oxide semiconductor film of the first transistor overlap the first gate of the first transistor and the second gate of the first transistor in a channel width direction.

8. The semiconductor device according to claim 1, wherein the first transistor has a channel length greater than or equal to 0.5 μ

m, and less than or equal to 4.5 μ

m.

18. The semiconductor device according to claim 1, wherein the second insulating film comprises an opening in the second portion of the first insulating film.

9. A semiconductor device comprising:

a first insulating film comprising a nitride;

a driver circuit comprising;

a first transistor including a first gate, a second gate, a semiconductor film between the first gate and the second gate, a second insulating film, and a third insulating film comprising a nitride, each of the second insulating film and the third insulating film between the second gate and the semiconductor film; and

a second transistor;

a pixel portion comprising;

a third transistor;

a liquid crystal element comprising;

a first transparent conductive film electrically connected to the third transistor;

a first conductive film over the first transparent conductive film; and

a liquid crystal layer between the first transparent conductive film and the first conductive film; and

a capacitor comprising;

a second transparent conductive film;

the first transparent conductive film over the second transparent conductive film; and

the third insulating film between the first transparent conductive film and the second transparent conductive film, the third insulating film is in contact with the second transparent conductive film,

wherein a first portion of the first insulating film comprises the second insulating film and the third insulating film over the second insulating film,

wherein a second portion of the first insulating film comprises the third insulating film in the capacitor,

wherein the first gate of the first transistor is electrically connected to the second gate of the first transistor,

wherein the second gate of the first transistor is in contact with the first insulating film,

wherein the first transparent conductive film is in contact with the first insulating film,

wherein one of a source and a drain of the first transistor is configured to receive a first potential,

wherein one of a source and a drain of the second transistor is configured to receive a second potential,

wherein the second potential is lower than the first potential, and

wherein the other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor.

10. The semiconductor device according to claim 9,

wherein the one of the source and the drain of the first transistor is further configured to receive the second potential, and

wherein the one of the source and the drain of the first transistor is configured to receive the first potential and the second potential alternately.

11. The semiconductor device according to claim 9, wherein each of a first channel formation region of the first transistor, a second channel formation region of the second transistor and a third channel formation region of the third transistor comprises an oxide semiconductor film.

12. The semiconductor device according to claim 10, wherein the oxide semiconductor film comprises In, Zn and O.

13. The semiconductor device according to claim 10, wherein the first insulating film comprises a height difference between the first portion of the first insulating film and the second portion of the first insulating film.

14. The semiconductor device according to claim 9, wherein the second transparent conductive film comprises In, Zn and O.

15. The semiconductor device according to claim 10, wherein end portions of the oxide semiconductor film of the first transistor overlap the first gate of the first transistor and the second gate of the first transistor in a channel width direction.

16. The semiconductor device according to claim 9, wherein the first transistor has a channel length greater than or equal to 0.5 μ

m, and less than or equal to 4.5 μ

m.

17. The semiconductor device according to claim 9, wherein the second gate of the first transistor and the first transparent conductive film comprise the same material.

19. The semiconductor device according to claim 9, wherein the second insulating film comprises an opening in the second portion of the first insulating film.

20. A semiconductor device comprising:

a first insulating film comprising a nitride;

a driver circuit comprising;

a first transistor including a first gate, a second gate, a semiconductor film between the first gate and the second gate, a second insulating film, and a third insulating film comprising a nitride, each of the second insulating film and the third insulating film between the second gate and the semiconductor film; and

a second transistor; and

a pixel portion comprising;

a third transistor;

a liquid crystal element comprising;

a first transparent conductive film electrically connected to the third transistor;

a first conductive film over the first transparent conductive film; and

a liquid crystal layer between the first transparent conductive film and the first conductive film; and

a capacitor comprising;

the first transparent conductive film;

a second transparent conductive film;

the first transparent conductive film over the second transparent conductive film; and

the third insulating film between the first transparent conductive film and the second transparent conductive film, the third insulating film is in contact with the second transparent conductive film,

wherein a first portion of the first insulating film comprises the second insulating film and the third insulating film over the second insulating film,

wherein a second portion of the first insulating film comprises the third insulating film in the capacitor,

wherein the first gate of the first transistor is electrically connected to the second gate of the first transistor,

wherein the second gate of the first transistor is in contact with the first insulating film,

wherein the first transparent conductive film is in contact with the first insulating film, and

wherein one of a source and a drain of the second transistor is electrically connected to one of a source and a drain of the first transistor.

21. The semiconductor device according to claim 20, wherein each of a first channel formation region of the first transistor, a second channel formation region of the second transistor and a third channel formation region of the third transistor comprises an oxide semiconductor film.

22. The semiconductor device according to claim 21, wherein the oxide semiconductor film comprises In, Zn and O.

23. The semiconductor device according to claim 21, wherein the second transparent conductive film comprises In, Zn and O.

24. The semiconductor device according to claim 21, wherein end portions of the oxide semiconductor film of the first transistor overlap the first gate of the first transistor and the second gate of the first transistor in a channel width direction.