Display device and process of producing the same

• US 6,800,871 B2
• Filed: 12/24/2002
• Issued: 10/05/2004
• Est. Priority Date: 12/27/2001
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sakaguchi, Kiyofumi, Matsuda, Hiroshi, Yonehara, Takao, Ikeda, Tsutomu, Kishi, Etsuro
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US10/327,147
• Publication Number:
  US 20030179191A1
• Time in Patent Office: 651 Days
• Field of Search: 257/30, 257/72, 438/458, 438/34, 438/29
• US Class Current: 257/30
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 21/76259 with separation/delamination along a porous layer

Abstract

The present invention relates to a configuration of a display element and forms switching circuits or peripheral circuits for driving pixels by transferring/disposing a semiconductor circuit formed on another substrate and disposes high performance transistors on the display substrate. The present invention also relates to a process of forming a circuit having switching elements for driving pixels and peripheral circuits for sending drive signals thereto on the substrate of the display element. A separation layer is formed on a second substrate and a semiconductor film is formed thereon. This semiconductor film having predetermined semiconductor circuits formed therein is bonded to the substrate of the display element and then electrical connection with a wire on the substrate is effected.

Claims

1. A display device comprising an image display element section and at least one of a switching circuit section

wherein the at least one of switching circuit section and peripheral circuit section is formed by performing one or more times a forming step of forming a circuit section comprising the at least one of switching circuit section and peripheral circuit section in a circuit film disposed on a second substrate and a transferring step of transferring and disposing the circuit film having the circuit section formed therein on the first substrate.

2. The display device according to claim 1, wherein the transferring step comprises a bonding step of bonding the circuit film to the first substrate and a separating step of separating the circuit film from the second substrate.

3. The display device according to claim 1, wherein the circuit film is transferred to and disposed on the first substrate through at least one third substrate.

4. The display device according to claim 1, wherein at least one of the first and the third substrates is a plastic film substrate.

5. The display device according to claim 1, wherein the material constituting the at least one of switching circuit section and peripheral circuit section comprises an organic semiconductor, amorphous silicon, polycrystalline silicon or monocrystalline silicon.

6. The display device according to claim 1, wherein the circuit film comprises a semiconductor element, a semiconductor integrated circuit, or an element of a metal/insulator/metal stack structure (MIM structure).

7. The display device according to claim 6, wherein the circuit film comprises at least one of a semiconductor element and a semiconductor integrated circuit formed in a monocrystalline silicon layer.

8. The display device according to claim 6, wherein the circuit film is comprised of a material having flexibility.

9. The display device according to claim 1, wherein the circuit film is at least a part of at least one of a semiconductor film and an insulating film formed on a separation layer formed on the second substrate.

10. The display device according to claim 9, wherein the separation layer is a porous layer or ion implanted layer.

11. The display device according to claim 1, which has a configuration such that the switching circuit section is disposed on a first surface of the first substrate and at least a part of the peripheral circuit section is disposed on a second surface of the first substrate.

12. The display device according to claim 1, which has a configuration such that at least one layer of the circuit film having at least a part of the peripheral circuit section formed therein is formed on the first substrate and the switching circuit section and the image display element section are successively formed thereon.

13. The display element according to claim 1, wherein electrical connection with the at least one of peripheral circuit section and switching circuit section contained in the circuit film is made through metallization.

14. A process of producing the display device as set forth in claim 1, comprising the following steps (1), (2), (3), (4) and (5):

(1) a step of preparing a second substrate comprising a separation layer and a semiconductor film successively stacked on a substrate;

(2) a forming step of forming at least one of switching circuit section and peripheral circuit section in the semiconductor film to form a circuit film;

(3) a separating step of separating the circuit film from the second substrate;

(4) a transferring step of transferring and disposing the circuit film onto the first substrate; and

(5) a step of forming an image display element section on the circuit film, provided that each said step is performed at least once.

15. The process according to claim 14, wherein the circuit film is transferred to and disposed on the first substrate through at least one third substrate.

16. The process according to claim 14, wherein in the transferring step, at least a part of the circuit film is stacked and disposed.

17. The process according to claim 14, wherein the second substrate is a semiconductor substrate, and wherein the formation of the circuit film comprises a step of forming a separation layer on the surface of the semiconductor, a step of forming a semiconductor film on the separation layer, and a step of forming the circuit section comprising at least one of a semiconductor element and a semiconductor integrated circuit in the semiconductor film.

18. The process according to claim 17, wherein the separation layer is a porous silicon layer.

19. The process according to claim 17, wherein the semiconductor film comprises at least one of monocrystalline silicon and a chemical compound semiconductor.

20. The process according to claim 14, wherein a cut groove is formed in a predetermined area on at least one of the second substrate having the circuit film formed therein and the circuit film, the circuit film is then bonded to the first substrate, the circuit film is separated from the second substrate, and the circuit film in the predetermined area is selectively transferred to and disposed on the first substrate.

21. The process according to claim 14, wherein prior to the separating step, a uniting step of bonding a support substrate onto the circuit film to unite the circuit film and the support substrate is performed, and in the separating step, the circuit film united with the support substrate is peeled and separated with the separation film being a boundary.

22. The process according to claim 14, wherein the circuit film is cut prior to the transferring step and at least one of the circuit film divided into chips is transferred to and disposed on the first substrate.

23. The process according to claim 15, wherein the circuit film is cut prior to the transferring step and in the transferring step, at least one of the circuit film divided into chips is transferred to and disposed on a third substrate and then the third substrate having the at least one chip-shape circuit film is disposed on the first substrate.

24. The process according to claim 14, wherein the image display element section is formed on the circuit film formed on the second substrate having the separation layer and then the circuit film is separated from the separation layer.

25. A process of producing the display device according to claim 14, wherein the circuit film is disposed in a face up direction on the first substrate and electrical connection is made through metallization.

26. A display device comprising:

an image display element section on a substrate;

a switching circuit section for driving the image display element section; and

a peripheral circuit section for driving the switching circuit section, each of the switching circuit section and the peripheral circuit section comprised of a circuit film,

wherein the switching circuit section and the image display section are stacked on the substrate and the peripheral circuit section is connected to the switching section by metallization.

27. The display device according to claim 26, wherein the circuit film is thin enough to form a metal film directly on the circuit film without wire breakage at a step portion of the circuit film.

28. The display device according to claim 26, wherein the circuit film is disposed on the substrate in a face up direction.

29. The display device according to claim 26, wherein the switching circuit section and the image display section are stacked on the peripheral circuit section.

30. The display device according to claim 26, wherein the peripheral circuit section is disposed on a same plane as that of the switching circuit section.

31. A display device comprising:

an image display element section on a substrate;

a switching circuit section for driving the image display element section; and

a peripheral circuit section for driving the switching circuit section, each of the switching circuit section and the peripheral circuit section comprised of a circuit film,

wherein the switching circuit section and the image display section are stacked on the substrate and the peripheral circuit section is connected to the switching section by a flexible wire.

32. The display device according to claim 31, wherein the peripheral circuit section is disposed on the back surface of the substrate.

33. The display device according to claim 31, wherein the peripheral circuit section is disposed on a film substrate and disposed on the back surface of the substrate.

34. A display device comprising:

an image display element section on a substrate;

a switching circuit section for driving the image display element section; and

a peripheral circuit section for driving the switching circuit section, each of the switching circuit section and the peripheral circuit section being comprised of a circuit film,

wherein wires are formed on the substrate and the circuit film is bonded on the substrate and connected to the wires through connecting means.

35. The display device according to claim 34, wherein the connecting means is a bump or an ACF film.

36. The display device according to claim 34, wherein the circuit film is supported by a supporting substrate.