Inkjet-fabricated integrated circuits

• US 20030059987A1
• Filed: 06/21/2002
• Published: 03/27/2003
• Est. Priority Date: 12/21/1999
• Status: Active Grant

• Current Assignee: FlexEnable Limited (Plastic Logic JSC)
• Original Assignee: Plastic Logic Limited (Plastic Logic JSC)
• Inventors: Sirringhaus, Henning, Friend, Richard Henry, Kawase, Takeo
• Granted Patent: US 7,176,040 B2
• Time in Patent Office: Days
• US Class Current: 438/149
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• 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: 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 71/135 using ink-jet 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 71/233 by photolithographic etching
• 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

Abstract

A method for forming an integrated circuit including at least two interconnected electronic switching devices, the method comprising forming at least part of the electronic switching devices by ink-jet printing.

Claims

1. A method for forming an integrated circuit including at least two interconnected electronic switching devices, the method comprising forming at least part of the electronic switching devices by ink-jet printing.

4. A method as claimed in any of claims 1 to 3, wherein the step of ink-jet printing comprises ink-jet printing electrically conductive material.

5. A method as claimed in claim 4, wherein the conductive material forms electrodes of the devices.

6. A method as claimed in any of claims 1 to 3, wherein the step of ink-jet printing comprises ink-jet printing semiconductive material.

7. A method as claimed in claim 6, wherein the semiconductive material forms active layers of the switching devices.

8. A method as claimed in claim 6 or 7, wherein the semiconductive material is a conjugated polymer.

9. A method as claimed in any of claims 6 to 8, wherein the semiconductive material is a conjugated block copolymer.

10. A method as claimed in any of claims 6 to 9, wherein the semiconductive material comprises a block copolymer comprising a first block of conjugated monomer units each linked by at least two covalent bonds, and a second block of monomer units, the block copolymer having an electron affinity greater than 3.0 eV or 3.5 eV.

11. A method as claimed in any of claims 6 to 9, wherein the semiconductive material comprises a block copolymer comprising a first block of conjugated monomer units each linked by at least two covalent bonds, and a second block of monomer units, the block copolymer having an ionisation potential in the range from 5.5 eV to 4.9 eV.

12. A method as claimed in claim 10 or 11, wherein the first block of monomer units comprises one or more of the group comprising a fluorene derivative, a phenylene derivative and an indenofluorene derivative and the second block of monomer units comprises one or more of the group comprising a thiophene derivative, a triarylamine derivative and a benzothiadiazole derivative.

13. A method as claimed in any of claims 5 to 8, wherein the semiconductive material is F8T2 or TFB.

14. A method as claimed in any of claims 5 to 8, wherein the semiconductive material comprises a liquid-crystalline conjugated polymer.

15. A method as claimed in claim 1, 2 or 3, wherein the step of inkjet printing comprises ink-jet printing a solvent on to localised regions of insulating layers of the devices so as to dissolve the insulating layers in the regions to leave voids extending through the layers.

16. A method as claimed in claim 15, comprising the step of depositing electrically conductive material in the voids.

17. A method as claimed in claim 1, 2 or 3, wherein the step of ink-jet printing comprises ink-jet printing a diffusive dopant on to localised regions of insulating layers of the devices so as to modify the insulating layers in the regions and thereby form a channel of electrically conductive material extending through the layers.

18. A method as claimed in any preceding claim, comprising the step of depositing electrically conductive material by ink-jet printing between the devices so as to electrically interconnect the devices.

19. A method as claimed in any preceding claim, comprising the step of depositing electrically insulating material by ink-jet printing between the devices so as to electrically isolate the devices.

20. A method as claimed in any preceding claim, wherein the devices are transistors.

21. A method as claimed in any preceding claim, wherein the step of ink-jet printing is performed by means of an ink-jet printer having at least one printing head operable under computer control to deposit material in a selected location on the substrate.

22. A method as claimed in claim 21, wherein the step of ink-jet printing includes the steps of detecting optical contrast one the substrate, and performing processing on the basis of the contrast in order to direct the printing head under computer control.

23. A method as claimed in claim 22, comprising the step of forming a display element over at least one of the transistors with an electrode of the display element in electrical connection with an electrode of one of the transistors.

36. An electronic device formed by a method according to any preceding claim.

2. A method for forming an integrated circuit comprising electronic switching devices and one or more of the following elements:

interconnects, via-hole interconnections, resistors, capacitors, diodes, display elements, the method comprising forming at least part of the switching elements and at least one of the other elements by ink-jet printing.

3. A method for forming an integrated circuit comprising electronic switching devices interconnected by via-hole interconnections;

the method comprising forming the via-hole connections by ink-jet printing.

24. A method for defining an electronic circuit from an electronic device array comprising a substrate and a plurality of transistors located on the substrate, each transistor—

having at least one interconnection electrode for allowing interconnection of the transistors;

the method comprising defining a pattern of interconnection between at least two of the transistors by ink-jet printing conductive material on the substrate so as to provide a conductive path between two of the interconnection electrodes.

25. A method as claimed in claim 24, wherein one of the said two transistors is part of a pre-connected functional block of transistors on the substrate.

26. A method as claimed in claim 24 or 25, wherein each of the transistors is formed from polymer material

27. A method as claimed in claim 25, wherein the polymer material comprises a conductive or semiconductive polymer.

28. A method as claimed in any of claims 24 to 27, wherein the substrate includes one or more passive circuit elements and the method includes the step of ink-jet printing conductive material on the substrate so as to provide a conductive path between an interconnection electrode of one of the transistors and one of the passive circuit elements.

29. A method as claimed in any of claims 24 to 28, wherein the substrate includes one or more further active circuit elements.

30. A method as claimed in claim 29, comprising the step of forming a display element over at least one of the transistors with an electrode of the display element in electrical connection with an electrode of one of the transistors.

31. A method as claimed in any of claims 24 to 30, wherein the step of ink-jet printing is performed by means of an ink-jet printer having at least one printing head operable under computer control to deposit material in a selected location on the substrate.

32. A method as claimed in any of claims 24 to 31, wherein the step of ink-jet printing includes the steps of detecting optical contrast one the substrate, and performing processing on the basis of the contrast in order to direct the printing head under computer control to achieve good registration accuracy with respect to a previously deposited pattern.

33. A method as claimed in any of claims 24 to 32, wherein the ink-jet printer is operable for depositing conductive and/or insulating material in order to define a user-selected circuit on the substrate by means of ink-jet printing.

34. A method as claimed in any of claims 24 to 32, comprising ink-jet printing a solvent on to localised regions of insulating layers of the devices so as to dissolve the insulating layers in the regions to leave voids extending through the layers, and depositing electrically conductive material in the voids.

35. A method as claimed in any of claims 24 to 34, wherein the substrate includes a structure between electrodes of the transistors for confining liquid deposited on the substrate in a pre-defined path between the electrodes by means of relative attraction and/or repellence for the liquid.

37. A method for defining an electronic device from a substrate comprising an array of first surface zones separated from each other by second surface zones, the method including the step of defining electrodes of a plurality of transistors on the substrate by depositing an electrically conductive polymer material from solution in a solvent that is relatively attracted by the first surface zones and relatively repelled by the second surface zones so as to cause the material to be segregated into regions corresponding to the first zones, and forming subsequent functional regions of the transistors so as to interconnect material in regions corresponding to adjacent first zones as electrodes of a single transistor.

38. A method as claimed in claim 37, the method comprising deposition of polymer transistors with channel lengths defined by the repelling surface regions, but with user-defined locations and with user-defined channel widths;

the method further comprising ink-jet printing of conductive material so as to provide interconnections between the transistors and/or opening of via-holes through insulating layers by local deposition of solvents and/or ink-jet printing of insulating layers in the overlap region of two interconnects

39. A method for defining an electronic device from an electronic device array comprising a substrate and a plurality of transistors or functional blocks of transistors located on the substrate, each transistor or functional block having at least one interconnection electrode for allowing interconnection of the transistors;

the method comprising defining a pattern of interconnection between at least two of the transistors by any one or more of the following steps;

ink-jet printing conductive material so as to provide a conductive path between two of interconnection electrodes;

opening a via-hole through an insulating layer of a transistor by local deposition of solvents on to an insulating layer of the transistor, and

ink-jet printing an insulative material in the region between two transistors or functional blocks.