Lamination and delamination technique for thin film processing
This invention discloses a releasable adhesion layer having good adhesion during high temperature fabrication process in the absence of light, and delaminating at a lower temperature in the presence of light. One embodiment of this invention is a film of polymer whose thermal decomposition temperature changes drastically upon photoexposure. These materials, prior to photoexposure, can withstand temperatures in the range of approximately 200° C. to 300° C. without decomposition, yet decompose at around 100° C. with photoexposure. The releasable adhesion layer can be used in a thermal transfer element, sandwiching a donor substrate and a transfer layer having a plurality of multicomponent transfer units. In the absence of light, the releasable adhesion layer can sustain high temperature processing of these multicomponent transfer units. By photoexposing according to a pattern, the photoexposed multicomponent transfer units can be selectively released at a low temperature to transfer to a receptor.
1. A method to form a device disposing on a receptor substrate, the device being formed by transferring a multicomponent transfer unit from a thermal transfer element to the receptor substrate, wherein
the multicomponent transfer unit comprises the device, and
the thermal transfer element comprises a donor substrate and a transfer layer with a releasable adhesion layer disposed between the donor substrate and the transfer layer,
the transfer layer comprising a plurality of multicomponent transfer units, and
the releasable adhesion layer comprising a polymer composition
having a low delamination temperature in the presence of light, whereby allowing the delamination of the adhesion layer to transfer the selected multicomponent units by exposing the selected multicomponent units to light; and
maintaining good adhesion between the donor substrate and the transfer layer at a temperature higher than the delamination temperature in the absence of light, whereby permitting processing the multicomponent transfer units at a temperature higher than the delamination temperature,
the method comprising
imagewise exposing the releasable adhesion layer to light; and
heating to decompose the releasable adhesion layer to transfer only the imagewise light-exposed areas to the receptor.
2. A method as in claim 1 , wherein the device comprises a component in electronic circuitry, an electronic device, a thin film transistor device, a memory device, a portion of a memory device, a logic device, a portion of a logic device, or a display device.
3. A method as in claim 1 , wherein the device is in electrical contact with other existing devices on the receptor.
4. A method as in claim 1 , wherein the receptor receiving surface comprises a releasable adhesion layer to form a thermal transfer element.
5. A method as in claim 1 , wherein the receptor substrate comprises a component in electronic circuitry, an electronic device, a thin film transistor device, a memory device, a portion of a memory device, a logic device, or a portion of a logic device.
6. A method as in claim 1 , wherein the device and the receptor each comprises a portion of a memory or logic device, and together form a complete memory or logic device.
7. A method as in claim 1 , wherein the device comprises a plurality of first electrodes of a cross bar memory device and the receptor comprises a plurality of second electrodes of a cross bar memory device, and together form a complete cross bar memory device.
8. A method as in claim 1 , wherein exposing the releasable adhesion layer to light comprises
illuminating the thermal transfer element with a light-emitting source according to a pattern covering the multicomponent transfer units.
9. A method as in claim 1 , wherein exposing the releasable adhesion layer to light comprises
illuminating the multicomponent transfer units with a light-emitting source.
10. A method as in claim 1 , wherein exposing the releasable adhesion layer to light comprises
illuminating the donor substrate with a light-emitting source.
11. A method as in claim 1 , further comprising the step of
contacting the receptor with the transfer layer of the thermal transfer element; before exposing the releasable adhesion layer to light.
12. A method as in claim 1 , wherein the main ingredient of the polymer composition is selected from a group consisting of phthalaldehyde, polycarbonates and polyformals.
13. A method as in claim 12 , wherein the polycarbonate comprises a plurality of a tertiary carbon next to one carbonate carbonyl per monomer unit.
14. A method as in claim 12 , wherein the polyformal comprises a bisallylic diol or a bisbenzylic diol per monomer unit.
15. A method as in claim 1 , wherein the polymer composition comprises an additive of a light-activated acid or base catalyst.
16. A method as in claim 1 , wherein the light source is selected from a group consisting of visible light, ultraviolet light, and x-ray.
17. A method as in claim 1 , further comprising an adhesive layer to facilitate adherence of the multicomponent transfer unit to the receptor.
18. A method as in claim 1 , wherein the donor substrate is at least partially transparent with respect to the light source.
19. A method as in claim 1 , wherein the multicomponent transfer unit is at least partially transparent with respect to the light source.
20. A method as in claim 1 , wherein the receptor is a second thermal transfer element and the multicomponent transfer unit of the first thermal transfer element is in electrical contact with the multicomponent transfer unit of the second thermal transfer element.
21. A method as in claim 1 , wherein the device is an organic electroluminescent device, an organic transistor, or an organic laser.