STRUCTURES AND METHODS FOR TESTING PRINTABLE INTEGRATED CIRCUITS

• US 20130221355A1
• Filed: 08/24/2011
• Published: 08/29/2013
• Est. Priority Date: 08/26/2010
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: Semprius, Inc.
• Inventors: Bower, Christopher, Menard, Etienne, Meitl, Matthew
• Granted Patent: US 9,142,468 B2
• Time in Patent Office: Days
• US Class Current: 257/48
• CPC Class Codes: G01R 31/26 Testing of individual semiconductor devices testing or measuring during manufacture or treatment H01L22/00; testing of photovoltaic devices H02S50/10
• CPC Class Codes: G01R 31/2644 Adaptations of individual semiconductor devices to facilitate the testing thereof
• CPC Class Codes: H01L 21/308 using masks H01L21/3063, H01L21/3065 take precedence
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/30 Structural arrangements specially adapted for testing or measuring during manufacture or treatment, or specially adapted for reliability measurements
• CPC Class Codes: H01L 22/32 Additional lead-in metallisation on a device or substrate, e.g. additional pads or pad portions, lines in the scribe line, sacrificed conductors arrangements for conducting electric current to or from the solid state body in operation H01L23/48
• CPC Class Codes: H01L 2221/6835 used as a support during build up manufacturing of active devices
• CPC Class Codes: H01L 2221/68381 Details of chemical or physical process used for separating the auxiliary support from a device or wafer
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/34 containing only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 33/48 characterised by the semiconductor body packages
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A substrate includes an anchor area (30) physically secured to a surface of the substrate (10) and at least one printable electronic component (20). The at least one printable electronic component includes an active layer (14) having one or more active elements thereon, and is suspended over the surface of the substrate by electrically conductive breakable tethers (40). The electrically conductive breakable tethers include an insulating layer and a conductive layer thereon that physically secure and electrically connect the at least one printable electronic component to the anchor area, and are configured to be preferentially fractured responsive to pressure applied thereto. Related methods of fabrication and testing are also discussed.

Claims

1. An integrated circuit structure, comprising:

a substrate;

an anchor area physically secured to a surface of the substrate; and

at least one printable electronic component comprising an active layer including one or more active elements thereon, the at least one printable electronic component being suspended over the surface of the substrate by electrically conductive breakable tethers that physically secure and electrically connect the at least one printable electronic component to the anchor area, wherein the electrically conductive breakable tethers comprise an insulating layer and a conductive layer thereon that are configured to be preferentially fractured responsive to pressure applied thereto.

2. The structure of claim 1, wherein the anchor area includes one or more electrical elements, and wherein the electrically conductive breakable tethers electrically connect the one or more active elements of the at least one electronic component to the one or more electrical elements of the anchor area.

3. The structure of claim 2, further comprising:

one or more contact pads on the substrate adjacent to and electrically coupled to the one or more electrical elements of the anchor area, wherein the one or more contact pads are sized and configured to be accessible to an external device.

4. The structure of claim 3, wherein the one or more contact pads are dimensionally larger than the one or more active elements and are arranged along a periphery of the substrate.

5. The structure of claim 3, wherein the active elements of the at least one electronic component comprise transistors, light emitting structures, light absorbing structures, metal wires, and/or electrical contact pads.

6. The structure of claim 5, wherein the electrical elements of the anchor area comprise transistors, light emitting structures, metal wires, and/or electrical contact pads.

7. The structure of claim 6, wherein the electrical elements of the anchor area comprise passive electrical elements.

8. The structure of claim 6, wherein the one or more electrical elements of the anchor area comprises a light emitting structure that is operable to illuminate responsive to a test signal supplied by the external device.

9. The structure of claim 1, wherein the anchor area is physically secured to the surface of the substrate by a sacrificial layer, and wherein the at least one electronic component is substantially free of the sacrificial layer and is completely detached from the surface of the substrate.

10. The structure of claim 9, wherein the anchor area comprises a portion of the active layer, and wherein the substrate comprises a source substrate on which the at least one electronic component and the anchor area are formed.

11. The structure of claim 3, wherein the anchor area comprises a first anchor area, and further comprising:

a second anchor area including one or more electrical elements thereon physically secured to the surface of the substrate adjacent to the first anchor area, wherein the electrical elements of the first anchor area are electrically connected to the electrical elements of the second anchor area.

12. The structure of claim 2, wherein the electrically conductive breakable tethers respectively comprise one or more conductive layers and at least one insulating layer that releasably secure the electronic component to the anchor area.

13. The structure of claim 12, wherein the electrically conductive breakable tethers further comprise respective stress-concentrating features configured to be preferentially fractured responsive to pressure applied thereto.

14. The structure of claim 13, wherein the stress-concentrating features comprise grooves or portions of the respective tethers having a reduced thickness relative to other portions thereof, and

wherein the stress concentrating features of the electrically conductive breakable tethers are configured to be preferentially fractured responsive to pressure applied by a stamp to transfer the at least one electronic component to a target substrate.

15. The structure of claim 12, wherein the electrically conductive breakable tethers respectively include first and second conductive layers with the insulating layer therebetween, wherein the first and second conductive layers are stacked or arranged in a side-by-side manner.

16. The structure of claim 1, wherein the at least one printable electronic component comprises:

a first printable electronic component physically secured and electrically connected to the anchor area by ones of the electrically conductive breakable tethers along a first side of the anchor area; and

a second printable electronic component physically secured and electrically connected to the anchor area by ones of the electrically conductive breakable tethers along a second side of the anchor area opposite the first side.

17. The structure of claim 1, wherein the active layer comprises a semiconductor layer.

18. The structure of claim 17, wherein the semiconductor layer is amorphous, polycrystalline, microcrystalline, or crystalline.

19. The structure of claim 17, wherein the semiconductor layer comprises silicon, gallium arsenide (GaAs), and/or a III-V compound semiconductor.

20. The structure of claim 1, wherein the electrically conductive breakable tethers include metal, polycrystalline semiconductor materials, or crystalline semiconductor materials.

21. A method of testing elements of a printable electronic component, the method comprising:

providing a substrate having an anchor area physically secured to a surface of the substrate and at least one printable electronic component including one or more active elements thereon, the at least one printable electronic component being suspended over the surface of the substrate by electrically conductive breakable tethers that physically secure and electrically connect the at least one printable electronic component to the anchor area and are configured to be preferentially fractured responsive to pressure applied thereto; and

providing an electrical signal to the one or more active elements of the printable electronic component through the electrically conductive breakable tethers via the anchor area.

22. The method of claim 21, wherein the electrical signal is configured to test a functionality of the one or more active elements.

23. The method of claim 22, wherein the anchor area includes one or more electrical elements, and further comprising:

confirming the functionality of the one or more active elements based on an electrical or optical response of the active elements of the at least one electronic component or the electrical elements of the anchor area to the electrical signal.

24. The method of claim 22, wherein the substrate further includes one or more contact pads adjacent to and electrically coupled to the anchor area and sized and configured to be accessible to an external device, and wherein providing the electrical signal comprises:

providing the electrical signal to the one or more contact pads from the external device to test the functionality of the one or more active elements of the at least one printable electronic component.

25. The method of claim 22, further comprising:

after providing the electrical signal to test the functionality of the one or more active elements, pressing a stamp against the at least one printable electronic component with a pressure sufficient to fracture the electrically conductive breakable tethers and separate the at least one printable electronic component from the anchor area.

26. The method of claim 21, wherein providing the substrate comprises:

providing a sacrificial layer on the substrate and an active layer on the sacrificial layer;

processing the active layer to form the at least one printable electronic component including the one or more active elements, the anchor area, and the electrically conductive breakable tethers that physically secure and electrically connect the at least one printable electronic component to the anchor area;

forming a trench extending through the active layer to the sacrificial layer to substantially separate the at least one printable electronic component from the anchor area except for the electrically conductive breakable tethers therebetween; and

selectively removing the sacrificial layer to suspend the at least one printable electronic component over the substrate by the electrically conductive breakable tethers.

27. A method of fabricating a printable electronic component, the method comprising:

providing a substrate, a sacrificial layer on the substrate, and an active layer on the sacrificial layer;

forming an insulating layer and a patterned conductive layer on the active layer;

processing the active layer to form an anchor area and at least one printable electronic component including one or more active elements therein;

forming a patterned trench extending through the active layer and the insulating layer to expose the sacrificial layer and substantially separate the at least one printable electronic component from the anchor area except for portions of the insulating layer and the patterned conductive layer extending therebetween; and

selectively removing the sacrificial layer to define electrically conductive breakable tethers comprising the portions of the insulating layer and the patterned conductive layer that physically secure and electrically connect the at least one printable electronic component to the anchor area to suspend the at least one printable electronic component over the substrate,

wherein the electrically conductive breakable tethers are configured to be preferentially fractured responsive to pressure applied thereto.

28. The method of claim 27, wherein processing the active layer further forms one or more electrical elements in the anchor area, and wherein the electrically conductive breakable tethers electrically connect the one or more active elements of the at least one electronic component to the one or more electrical elements of the anchor area.

29. The method of claim 28, wherein forming the patterned trench comprises:

patterning the insulating layer using the patterned conductive layer as a mask to form the portions of the insulating layer and the patterned conductive layer that define the electrically conductive breakable tethers.

30. The method of claim 29, wherein the patterned conductive layer comprises one or more patterned metal layers or one or more patterned polysilicon layers.

31. The method of claim 28, further comprising:

patterning the conductive layer and the one or more active elements of the at least one printable electronic component or the one or more electrical elements of the anchor area in a common processing step.

32. The method of claim 28, wherein the electrically conductive breakable tethers are formed using at least one common mask used to form at least some of the one or more active elements of the at least one printable electronic component or at least some of the one or more electrical elements of the anchor area.

33. The method of claim 27, wherein the sacrificial layer is selectively removed such that the anchor area is physically secured to the surface of the substrate by a remaining portion of the sacrificial layer, and such that the at least one electronic component is substantially free of the sacrificial layer and is completely detached from the surface of the substrate.

34. The method of claim 27, wherein forming the patterned trench comprises:

performing a shallow etch of the active layer to define a preliminary trench that does not expose the sacrificial layer;

forming a protective layer pattern on the active layer and the portions of the insulating layer and the patterned conductive layer extending between the at least one electronic component and the anchor area, the protective layer pattern exposing at least a portion of the active layer; and

then

etching the exposed portion of the active layer to expose the sacrificial layer.

35. The method of claim 34, further comprising:

providing a step structure in the active layer and within the preliminary trench prior to forming the protective layer pattern thereon such that the active layer is thicker in portions adjacent the anchor area and the at least one printable electronic component.

36. The method of claim 27, further comprising:

forming a deep implant region in the active layer, the deep implant region comprising a material having a different etching characteristic than the active layer.

37. The method of claim 36, wherein the deep implant region is formed in portions of the active layer adjacent the anchor area and the at least one printable electronic component.

38. The method of claim 27, further comprising:

forming a filled trench structure in the active layer and extending through the active layer to the sacrificial layer, the filled trench structure having a different etching characteristic than the active layer.

39. The method of claim 38, wherein the filled trench structure comprises a field oxide layer and is formed in a portion of the active region between the at least one electronic component and the anchor area.