Semiconductor device having a storage capacitor

• US 6,963,084 B2
• Filed: 01/16/2004
• Issued: 11/08/2005
• Est. Priority Date: 09/06/2000
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Isobe, Atsuo, Takayama, Toru, Arao, Tatsuya
• Primary Examiner(s): Hu, Shouxiang
• Application Number:
  US10/759,683
• Publication Number:
  US 20040144983A1
• Time in Patent Office: 662 Days
• Field of Search: 257/59, 257/40, 257/57, 257/61, 257/66, 257/72, 257/532, 257/534, 349/39, 349 42- 43, 349/47, 349/139, 438/48, 438/128, 438/149, 438/151, 438/157, 438/283, 438/255, 438/398
• US Class Current: 257/59
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• 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 29/66742 Thin film unipolar transistors
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays

Abstract

In a semiconductor device having a substrate which has a metal surface, an insulating film which is formed on the substrate having the metal surface, and a pixel unit which is formed on the insulating film; the pixel unit includes a TFT, and wiring lines connected with the TFT, and a storage capacitor is constituted by the substrate (11) having the metal surface, the insulating film (12), and the wiring line (21). As the insulating film is thinner, and as the area of a region where the insulating film and the wiring line lie in contact is larger, the storage capacitor is endowed with a larger capacity.

Claims

1. A semiconductor device comprising:

a substrate having a metal surface;

a base insulating film formed on the substrate having the metal surface;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film; and

a storage capacitor comprising a portion of the substrate having the metal surface, the exposed portion of the base insulating film, and the metal wiring.

2. A semiconductor device according to claim 1, wherein the metal surface comprises a stainless steel.

3. A semiconductor device according to claim 1, wherein the switching thin film transistor is a p-channel thin film transistor.

4. A semiconductor device according to claim 1, wherein the current controlling thin film transistor is an n-channel thin film transistor.

5. A semiconductor device according to claim 1, wherein the semiconductor device is a light-emitting device.

6. A semiconductor device according to claim 1, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.

7. A semiconductor device comprising:

a substrate having a metal surface;

a base insulating film formed on the substrate having the metal surface;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film and electrically connected to the gate electrode of the current controlling thin film transistor; and

a storage capacitor comprising a portion of the substrate having the metal surface, the exposed portion of the base insulating film, and the metal wiring.

8. A semiconductor device according to claim 7, wherein the metal surface comprises a stainless steel.

9. A semiconductor device according to claim 7, wherein the switching thin film transistor is a p-channel thin film transistor.

10. A semiconductor device according to claim 7, wherein the current controlling thin film transistor is an n-channel thin film transistor.

11. A semiconductor device according to claim 7, wherein the semiconductor device is a light-emitting device.

12. A semiconductor device according to claim 7, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.

13. A semiconductor device comprising:

a substrate having a metal surface;

a base insulating film formed on the substrate having the metal surface;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film and electrically connected to the semiconductor layer of the switching thin film transistor; and

a storage capacitor comprising a portion of the substrate having the metal surface, the exposed portion of the base insulating film, and the metal wiring.

14. A semiconductor device according to claim 13, wherein the metal surface comprises a stainless steel.

15. A semiconductor device according to claim 13, wherein the switching thin film transistor is a p-channel thin film transistor.

16. A semiconductor device according to claim 13, wherein the current controlling thin film transistor is an n-channel thin film transistor.

17. A semiconductor device according to claim 13, wherein the semiconductor device is a light-emitting device.

18. A semiconductor device according to claim 13, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.

19. A semiconductor device comprising:

a metal substrate;

a base insulating film formed on the metal substrate;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film; and

a storage capacitor comprising a portion of the metal substrate, the exposed portion of the base insulating film, and the metal wiring.

20. A semiconductor device according to claim 19, wherein the metal substrate comprises a stainless steel substrate.

21. A semiconductor device according to claims 19, wherein the switching thin film transistor is a p-channel thin film transistor.

22. A semiconductor device according to claim 19, wherein the current controlling thin film transistor is an n-channel thin film transistor.

23. A semiconductor device according to claim 19, wherein the semiconductor device is a light-emitting device.

24. A semiconductor device according to claim 19, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.

25. A semiconductor device comprising:

a metal substrate;

a base insulating film formed on the metal substrate;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film and electrically connected to the gate electrode of the current controlling thin film transistor; and

a storage capacitor comprising a portion of the metal substrate, the exposed portion of the base insulating film, and the metal wiring.

26. A semiconductor device according to claim 25, wherein the metal substrate comprises a stainless steel substrate.

27. A semiconductor device according to claim 25, wherein the switching thin film transistor is a p-channel thin film transistor.

28. A semiconductor device according to claim 25, wherein the current controlling thin film transistor is an n-channel thin film transistor.

29. A semiconductor device according to claim 25, wherein the semiconductor device is a light-emitting device.

30. A semiconductor device according to claim 25, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.

31. A semiconductor device comprising:

a metal substrate;

a base insulating film formed on the metal substrate;

a switching thin film transistor and a current controlling thin film transistor, both formed on the base insulating film in a pixel unit, wherein each of the thin film transistors comprises a semiconductor layer and a gate electrode with a gate insulating film interposed therebetween;

an interlayer insulating film formed over the switching thin film transistor and the current controlling thin film transistor, wherein a portion of the interlayer insulating film is removed so as to expose a portion of the base insulating film;

a metal wiring formed on the exposed portion of the base insulating film and electrically connected to the semiconductor layer of the switching thin film transistor; and

a storage capacitor comprising a portion of the metal substrate, the exposed portion of the base insulating film, and the metal wiring.

32. A semiconductor device according to claim 31, wherein the metal substrate comprises a stainless steel substrate.

33. A semiconductor device according to claim 31, wherein the switching thin film transistor is a p-channel thin film transistor.

34. A semiconductor device according to claim 31, wherein the current controlling thin film transistor is an n-channel thin film transistor.

35. A semiconductor device according to claim 31, wherein the semiconductor device is a light-emitting device.

36. A semiconductor device according to claim 31, wherein the semiconductor device is one selected from the group consisting of a portable telephone, a video camera, a digital camera, a goggle type display, a personal computer, a DVD player, an electronic book, and a portable information terminal.