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 an integrated device fabrication, the integrated device comprising a plurality of pixels, each pixel comprising at least a micro device integrated on a receiver substrate, the method comprising:
extending an active area of a first pixel to an area larger than an area of a first micro device of the first pixel by patterning of a filler layer about the first micro device; and
forming a sidewall reflective layer around the patterned filler layer defining the first pixel.
2 . The method according to claim 1 , wherein the sidewall reflective covering at least a portion of one side of the patterned filler layer and confining at least a portion of incoming or outgoing light within the active area of the first pixel.
3 . The method according to claim 2 , wherein the sidewall reflective layer is fabricated as an electrode of the first micro device.
4 . The method according to claim 1 , further comprising:
patterning the filler layer about a second micro device and between the first micro device and the second micro device of the first pixel.
5 . The method according to claim 1 , wherein the patterned filler layer is comprised of a dielectric filler material.
6 . The method according to claim 1 , further comprising:
forming a dielectric layer between the sidewall reflective layer and the patterned filler layer.
7 . The method according to claim 1 , further comprising;
forming a transparent conductive layer over a top of the first micro device; and
forming a contact pad at a bottom of the first micro device, wherein the contact pad is formed with a concave structure capable of enhancing the outcoupling of light from the first micro device.
8 . The method according to claim 1 , wherein the sidewall reflective layer is fabricated as a portion of the electrode of the first micro device.
9 . The method according to claim 1 , wherein the sidewall reflective layer is covered by a black matrix to reduce an ambient reflection of the integrated device.