Micro device integration into system substrate
Post-processing steps for integrating of micro devices into system (receiver) substrate or improving the performance of the micro devices after transfer. Post processing steps for additional structures such as reflective layers, fillers, black matrix or other layers may be used to improve the out coupling or confining of the generated LED light. Dielectric and metallic layers may be used to integrate an electro-optical thin film device into the system substrate with transferred micro devices. Color conversion layers may be integrated into the system substrate to create different outputs from the micro devices.
1. A method of integrated device fabrication, the device comprising a plurality of pixels, each comprising at least one light emitting micro device and a thin-film light emitting electro-optical device integrated on a receiver substrate, the method comprising:
mounting a first and a second contact pad on the receiver substrate for each micro device and each thin-film electro-optical device, respectively;
integrating the at least one light emitting micro device onto the receiver substrate;
forming a dielectric layer around each micro device and covering the first and second contact pad;
subsequent to the integration of the at least one micro device, integrating at the least one thin-film light emitting electro-optical device onto the receiver substrate including forming a bottom electrode for each thin-film electro-optical device extending from the second contact pad through the dielectric layer and along a top of the dielectric layer; and
integrating at least one reflector capable of directing light from each micro device and each thin-film electro-optical device in a same direction.
2. The method according to claim 1 , wherein integrating the at least one thin-film electro-optical device comprises:
forming a top electrode over the thin-film electro-optical device; and
forming an opening for light from the micro device through at least one of the bottom electrode and the top electrode.
3. The method according to claim 1 , wherein each of the first contact pad are transparent; whereby an optical path for the micro device is through the receiver substrate.
4. The method according to claim 1 , further comprising:
covering each micro device with a planarization layer; and
fabricating the top electrode which serves as a shared electrode for both one of the thin-film electro-optical device and one of the light emitting micro device,
wherein a portion of the shared top electrode extends through an opening in the planarization layer into contact with the micro device; and wherein the thin-film electro-optical device is formed selectively to not cover the opening.
5. The method according to claim 1 , wherein each second contact pad is extended to form the at least one reflector for reflecting light from the micro device and the thin-film electrooptical device.
6. The method according to claim 1 , wherein the at least one reflector comprises a reflective layer on the receiver substrate.
7. A method of integrated device fabrication, the device comprising a plurality of pixels, each comprising at least one micro device and a thin-film electro-optical device, integrated on a receiver substrate, the method comprising:
integrating at least one light emitting micro device onto the receiver substrate;
subsequent to the integration of the at least one light emitting micro device, integrating at least one thin film light emitting electro-optical device onto the receiver substrate including a top and a bottom electrode; and
integrating at least one reflector capable of directing light from each light emitting micro device and each thin-film light emitting electro-optical device in a same direction;
wherein integrating the at least one thin-film light emitting electro-optical device comprises forming an opening for light from the light emitting micro device through at least one of the top electrode and the bottom electrode.
8. The method according to claim 7 , wherein each second contact pad is extended to form the at least one reflector for reflecting light from the micro device and the thin-film electro-optical device.
9. The method according to claim 7 , wherein the at least one reflector comprises a reflective layer on the receiver substrate.