Semiconductor device and method of fabricating the same

• US 7,973,312 B2
• Filed: 03/22/2010
• Issued: 07/05/2011
• Est. Priority Date: 03/06/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Nakajima, Setsuo, Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): SEFER, AHMED N
• Application Number:
  US12/728,487
• Publication Number:
  US 20100171895A1
• Time in Patent Office: 470 Days
• Field of Search: 257/59, 257/72, 257/350, 349/28, 349/39, 349/42, 349/46
• US Class Current: 257/59
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask

Abstract

A display device includes a main body, a support stand, and a display portion. The display portion includes a pixel having a TFT and a capacitor. The capacitor includes a capacitor electrode on an insulating surface, an insulating film on the capacitor electrode, and a pixel electrode of the TFT on the insulating film.

Claims

1. A display device comprising:

a thin film transistor, the thin film transistor comprising;

a gate electrode formed over a substrate;

an insulating film formed over the gate electrode;

a semiconductor film formed over the insulating film;

source and drain regions formed over the semiconductor film;

a source electrode over the source region; and

a drain electrode formed over the drain region;

a pixel electrode comprising a transparent conductive material, formed over the substrate, and connected to the drain electrode;

a source wiring being continuous to the source electrode, formed over the insulating film;

a gate wiring being continuous to the gate electrode, formed over the substrate;

a passivation film formed over the source electrode and the drain electrode, the passivation film being in contact with a portion of the semiconductor film between the source electrode and the drain electrode; and

a capacitor, the capacitor comprising;

a capacitor wiring formed over the substrate, wherein the capacitor wiring comprises a same material as the gate electrode;

the insulating film formed over the capacitor wiring; and

the pixel electrode formed over the capacitor wiring with the insulating film interposed therebetween,

wherein the capacitor wiring extends substantially in parallel with the gate wiring at least in a pixel portion,

wherein the capacitor wiring is electrically connected to a terminal portion, and

wherein the terminal portion is formed in an edge portion of the substrate.

2. The display device according to claim 1, wherein the pixel electrode is located below the passivation film.

3. The display device according to claim 1, wherein an end surface of the drain region lies substantially in register with an end surface of the pixel electrode and an end surface of the drain electrode.

4. The display device according to claim 1, wherein the pixel electrode is in contact with an end surface of the drain region, an end surface of the semiconductor film and an end surface of the drain electrode.

5. The display device according to claim 1, further comprising a transparent conductive film formed over and along with the source wiring, comprising the same material as the pixel electrode.

6. The display device according to claim 5, wherein the transparent conductive film extends beyond both side edges of the source wiring.

7. The display device according to claim 5, wherein the transparent conductive film is electrically separated from the pixel electrode.

8. The display device according to claim 5, wherein an end surface of the source region lies substantially in register with an end surface of the transparent conductive film and an end surface of the source electrode.

9. The display device according to claim 5, wherein the transparent conductive film is in contact with an end surface of the source region, an end surface of the semiconductor film and an end surface of the source electrode.

10. The display device according to claim 1, wherein the terminal portion is electrically connected to a flexible printed circuit.

11. The display device according to claim 1, wherein the gate wiring is electrically connected to the terminal portion.

12. The display device according to claim 1, wherein the passivation film comprises at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a tantalum oxide film.

13. A display device comprising:

a thin film transistor, the thin film transistor comprising;

a gate electrode formed over a substrate;

an insulating film formed over the gate electrode;

a first semiconductor film formed over the insulating film;

source and drain regions formed over the first semiconductor film;

a source electrode over the source region; and

a drain electrode formed over the drain region;

a pixel electrode comprising a transparent conductive material, formed over the substrate, and connected to the drain electrode;

a source wiring being continuous to the source electrode, formed over the insulating film and second and third semiconductor films, wherein the third semiconductor film is formed over the second semiconductor film;

wherein the second semiconductor film is continuous to the first semiconductor film, and comprises the same material as the first semiconductor film, and

wherein the third semiconductor film is continuous to the source region, and comprises the same material as the source region,

a gate wiring being continuous to the gate electrode, formed over the substrate;

a passivation film formed over the source electrode and the drain electrode, the passivation film being in contact with a portion of the first semiconductor film between the source electrode and the drain electrode; and

a capacitor, the capacitor comprising;

a capacitor wiring formed over the substrate, wherein the capacitor wiring comprises a same material as the gate electrode;

the insulating film formed over the capacitor wiring; and

the pixel electrode formed over the capacitor wiring with the insulating film interposed therebetween,

wherein the capacitor wiring extends substantially in parallel with the gate wiring at least in a pixel portion,

wherein the capacitor wiring is electrically connected to a terminal portion, and

wherein the terminal portion is formed in an edge portion of the substrate.

14. The display device according to claim 13, wherein the pixel electrode is located below the passivation film.

15. The display device according to claim 13, wherein an end surface of the drain region lies substantially in register with an end surface of the pixel electrode and an end surface of the drain electrode.

16. The display device according to claim 13, wherein the pixel electrode is in contact with an end surface of the drain region, an end surface of the first semiconductor film and an end surface of the drain electrode.

17. The display device according to claim 13, further comprising a transparent conductive film formed over and along with the source wiring, comprising the same material as the pixel electrode.

18. The display device according to claim 17, wherein the transparent conductive film extends beyond both side edges of the source wiring.

19. The display device according to claim 17, wherein the transparent conductive film is electrically separated from the pixel electrode.

20. The display device according to claim 17, wherein an end surface of the source region lies substantially in register with an end surface of the transparent conductive film and an end surface of the source electrode.

21. The display device according to claim 17, wherein the transparent conductive film is in contact with an end surface of the source region, an end surface of the first semiconductor film and an end surface of the source electrode.

22. The display device according to claim 13, wherein the terminal portion is electrically connected to a flexible printed circuit.

23. The display device according to claim 13, wherein the gate wiring is electrically connected to the terminal portion.

24. The display device according to claim 13, wherein the passivation film comprises at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a tantalum oxide film.

25. A display device comprising:

a thin film transistor, the thin film transistor comprising;

a gate electrode formed over a substrate;

an insulating film formed over the gate electrode;

a semiconductor film formed over the insulating film;

source and drain regions formed over the semiconductor film;

a source electrode over the source region; and

a drain electrode formed over the drain region;

a pixel electrode comprising a transparent conductive material, formed over the substrate, and connected to the drain electrode;

a source wiring being continuous to the source electrode, formed over the insulating film;

a gate wiring being continuous to the gate electrode, formed over the substrate;

a passivation film formed over the source electrode and the drain electrode, the passivation film being in contact with a portion of the semiconductor film between the source electrode and the drain electrode;

an alignment film formed over the passivation film; and

a capacitor, the capacitor comprising;

a capacitor wiring formed over the substrate, wherein the capacitor wiring comprises a same material as the gate electrode;

the insulating film formed over the capacitor wiring; and

the pixel electrode formed over the capacitor wiring with the insulating film interposed therebetween,

wherein the capacitor wiring extends substantially in parallel with the gate wiring at least in a pixel portion,

wherein the capacitor wiring is electrically connected to a terminal portion, and

wherein the terminal portion is formed in an edge portion of the substrate.

26. The display device according to claim 25, wherein the pixel electrode is located below the passivation film.

27. The display device according to claim 25, wherein an end surface of the drain region lies substantially in register with an end surface of the pixel electrode and an end surface of the drain electrode.

28. The display device according to claim 25, wherein the pixel electrode is in contact with an end surface of the drain region, an end surface of the semiconductor film and an end surface of the drain electrode.

29. The display device according to claim 25, further comprising a transparent conductive film formed over and along with the source wiring, comprising the same material as the pixel electrode.

30. The display device according to claim 29, wherein the transparent conductive film extends beyond both side edges of the source wiring.

31. The display device according to claim 29, wherein the transparent conductive film is electrically separated from the pixel electrode.

32. The display device according to claim 29, wherein an end surface of the source region lies substantially in register with an end surface of the transparent conductive film and an end surface of the source electrode.

33. The display device according to claim 29, wherein the transparent conductive film is in contact with an end surface of the source region, an end surface of the semiconductor film and an end surface of the source electrode.

34. The display device according to claim 25, wherein the terminal portion is electrically connected to a flexible printed circuit.

35. The display device according to claim 25, wherein the gate wiring is electrically connected to the terminal portion.

36. The display device according to claim 25, wherein the passivation film comprises at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a tantalum oxide film.

37. A display device comprising:

a thin film transistor, the thin film transistor comprising;

a gate electrode formed over a substrate;

an insulating film formed over the gate electrode;

a first semiconductor film formed over the insulating film;

source and drain regions formed over the first semiconductor film;

a source electrode over the source region; and

a drain electrode formed over the drain region;

a pixel electrode comprising a transparent conductive material, formed over the substrate, and connected to the drain electrode;

a source wiring being continuous to the source electrode, formed over the insulating film and second and third semiconductor films, wherein the third semiconductor film is formed over the second semiconductor film;

wherein the second semiconductor film is continuous to the first semiconductor film, and comprises the same material as the first semiconductor film, and

wherein the third semiconductor film is continuous to the source region, and comprises the same material as the source region,

a gate wiring being continuous to the gate electrode, formed over the substrate;

a passivation film formed over the source electrode and the drain electrode, the passivation film being in contact with a portion of the first semiconductor film between the source electrode and the drain electrode;

an alignment film formed over the passivation film; and

a capacitor, the capacitor comprising;

a capacitor wiring formed over the substrate, wherein the capacitor wiring comprises a same material as the gate electrode;

the insulating film formed over the capacitor wiring; and

the pixel electrode formed over the capacitor wiring with the insulating film interposed therebetween,

wherein the capacitor wiring extends substantially in parallel with the gate wiring at least in a pixel portion,

wherein the capacitor wiring is electrically connected to a terminal portion, and

wherein the terminal portion is formed in an edge portion of the substrate.

38. The display device according to claim 37, wherein the pixel electrode is located below the passivation film.

39. The display device according to claim 37, wherein an end surface of the drain region lies substantially in register with an end surface of the pixel electrode and an end surface of the drain electrode.

40. The display device according to claim 37, wherein the pixel electrode is in contact with an end surface of the drain region, an end surface of the first semiconductor film and an end surface of the drain electrode.

41. The display device according to claim 37, further comprising a transparent conductive film formed over and along with the source wiring, comprising the same material as the pixel electrode.

42. The display device according to claim 41, wherein the transparent conductive film extends beyond both side edges of the source wiring.

43. The display device according to claim 41, wherein the transparent conductive film is electrically separated from the pixel electrode.

44. The display device according to claim 41, wherein an end surface of the source region lies substantially in register with an end surface of the transparent conductive film and an end surface of the source electrode.

45. The display device according to claim 41, wherein the transparent conductive film is in contact with an end surface of the source region, an end surface of the first semiconductor film and an end surface of the source electrode.

46. The display device according to claim 37, wherein the terminal portion is electrically connected to a flexible printed circuit.

47. The display device according to claim 37, wherein the gate wiring is electrically connected to the terminal portion.

48. The display device according to claim 37, wherein the passivation film comprises at least one of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and a tantalum oxide film.