Forming interconnects using locally deposited solvents

• US 7,098,061 B2
• Filed: 06/21/2002
• Issued: 08/29/2006
• Est. Priority Date: 12/21/1999
• Status: Expired due to Term

• Current Assignee: FlexEnable Limited (Plastic Logic JSC)
• Original Assignee: Plastic Logic Limited (Plastic Logic JSC)
• Inventors: Sirringhaus, Henning, Kawase, Takeo, Henry Friend, Richard
• Primary Examiner(s): GURLEY, LYNNE ANN
• Application Number:
  US10/176,173
• Publication Number:
  US 20030060038A1
• Time in Patent Office: 1,530 Days
• Field of Search: 438/30, 438/82, 438/99, 438/149, 438/161, 438/623, 438780-781, 438789-790, 438793-794
• US Class Current: 438/30
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 21/31133 by chemical means
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/471 the gate dielectric comprising only organic materials
• CPC Class Codes: H10K 19/10 comprising field-effect transistors
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/80 Constructional details
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing
• CPC Class Codes: H10K 71/191 characterised by provisions for the orientation or alignment of the layer to be deposited
• CPC Class Codes: H10K 71/236 using printing techniques, e.g. applying the etch liquid using an ink jet printer
• CPC Class Codes: H10K 71/30 Doping active layers, e.g. electron transporting layers
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes
• CPC Class Codes: H10K 71/621 Providing a shape to conductive layers, e.g. patterning or selective deposition

Abstract

A method for forming an electronic device, comprising: forming a first conductive or semiconductive layer; forming a sequence of at least on insulating layer and at least one semiconducting layer over the first conductive or semiconductive layer; locally depositing solvents at a localised region of the insulating layer so as to dissolve the sequence of insulating and semiconducting layers in the region to leave a void extending through the sequence of layer; and depositing conductive or semiconductive material in the void.

Claims

1. A method for forming an electronic device, comprising:

forming a first conductive or semiconductive layer;

forming a sequence of at least one insulating layer and at least one semiconducting layer over the first conductive or semiconductive layer;

locally depositing solvents at a localised region of the sequence so as to than a void in the sequence with material dissolved to form said void being redeposited at a side of the void; and

depositing conductive or semiconductive material in the void.

2. A method as claimed in claim 1, wherein the solvents are deposited simultaneously.

3. A method as claimed in claim 1, wherein the solvents arc deposited sequentially.

4. A method as claimed in claim 1, wherein the first layer is substantially insoluble in the said solvent or solvents.

5. A method as claimed in claim 4, wherein the first layer comprises a semiconductive conjugated polymer.

6. A method as claimed in claim 4, wherein the first layer comprises F8T2 or TFB.

7. A method as claimed in claim 4, wherein the first layer is an active layer of the electronic device.

8. A method as claimed in claim 4, comprising the step of depositing a conductive layer under the first layer.

9. A method as claimed in claim 8, wherein the conductive layer is an electrode of the electronic device.

10. A method as claimed in claim 4, wherein the first layer comprises a conductive conjugated polymer.

11. A method as claimed in claim 4, wherein the volume of the said solvent or solvents is greater than that required to dissolve the sequence of insulating and semiconducting layers in the region.

12. A method as claimed in claim 1, comprising forming a further conductive or semiconductive layer over the sequence of insulating and semiconducting layers or the insulating layer and in contact with the material in the void.

13. A method as claimed in claim 12, wherein the first conductive a semiconductive layer forms an electrode or an interconnect.

14. A method as claimed in claim 12, wherein the further conductive or semiconductive layer forms an electrode or an interconnect.

15. A method as claimed in claim 1, wherein the said solvent or solvents are deposited by ink jet printing.

16. A method as claimed in claim 15, wherein the said solvent or solvents are deposited as a single droplet by ink-jet printing.

17. A method as claimed in claim 15, wherein the said solvent or solvents are deposited as a plurality of droplets by ink-jet printing.

18. A method as claimed in claim 1, wherein the boiling point of the said solvent or of the said solvents in combination is greater than 80°

C.

19. A method as claimed in claim 1, wherein the boiling point of the said solvent or of the said solvents in combination is greater than 100°

C.

20. A method as claimed in claim 1, wherein the hailing point of the said solvent or of the said solvents in combination is less than 100°

C.

21. A method as claimed in claim 1, wherein each of the insulating and semiconducting layers has a solubility greater than 1 weight percent per volume in one or more of the said solvents.

22. A method as claimed in claim 1, wherein each of the insulating and semiconducting layers has a solubility greater than 2 weight percent per volume in one or more of the said solvents.

23. A method as claimed in claim 1, in which the volume of deposited solvent is less than 50 pl.

24. A method as claimed in claim 1, in which the volume of deposited solvent is less than 20 pl.

25. A method as claimed in claim 1, in which the volume of deposited solvent is less than 5 pl.

26. A method as claimed in claim 1, in which the contact angle of the deposited solvent on the layer or sequence of layers to be dissolved is larger than 50°

, but less than 90°

.

27. A method as claimed in claim 1, in which the contact angle of the deposited solvent on the layer or sequence of layers to be dissolved is larger than 20°

, bin less than 90°

.

28. A method as claimed in claim 1, in which the contact angle of the deposited solvent on the layer or sequence of layers to be dissolved is larger than 50°

, but less than 90°

.

29. A method as claimed in claim 1, in which the surface of the layer or sequence of layers to be dissolved has been treated in order to provide a greater repellence for the deposited solvent droplets.

30. A method as claimed in claim 29, in which the surface treatment is provided by deposition of a self-assembled monolayer.

31. A method as claimed in claim 1, wherein the electronic device is a transistor and the material deposited in the void forms a via hole interconnect between electrodes and/or interconnect lines in different layers of the device.

32. A method as claimed in claim 1, wherein the solvent or one of the solvents is an alcohol.

33. A method as claimed in claim 1, wherein the solvent or one of the solvents is IPA or methanol.

34. A method as claimed in claim 1, comprising the step of forming a confinement structure for confining the solvent or solvents to the localised region by means of its wetting properties.

35. A method as in claim 34, wherein the confinement structure is provided by a self-assembled monolayer.

36. A method as claimed in any claim 1 wherein the insulating layer comprises PVP.

37. A method as claimed in claim 1, wherein one of the insulating layer and a layer directly underlying it is soluble in a polar solvents and the other of the insulating layer and the layer directly underlying it is soluble in a non-polar solvent.

38. A method as claimed in claim 1, wherein the local deposition is carried out using a printing technique.

39. A method as claimed in claim 1, wherein the local deposition of the solvents is carried out by locally depositing the solvents as droplets by ink-jet printing.

40. A method for forming an electronic device, comprising:

forming a first conductive or semiconductive layer;

forming a soluble insulating layer over the first conductive or semiconductive layer;

locally depositing a solvent at a localised region of the insulating layer so as to form a void in the insulating layer with material dissolved to form said void redeposited at a side of the void; and

depositing conductive or semiconductive material in the void.

41. A method as claimed in claim 40, wherein the insulating layer has a solubility greater than 1 weight percent per volume in the said solvent.

42. A method as claimed in claim 40, wherein the insulating layer has a solubility greater than 2 weight percent per volume in the said solvent.

43. A method as claimed in claim 40, wherein the local deposition is carried alit using a printing technique.

44. A method as claimed in claim 40, wherein the local deposition of the solvent is carried out by local depositing the solvent as one or more droplets by ink-jet printing.