Pendeo-Epitaxy of GaN for µ-DISplays – PEGADIS

Micro-LEDs are the basic constituent of high-resolution micro-displays. But, when of micrometer size, the GaN based µ-LEDs have reduced efficiencies because of detrimental edge effects associated to the etching step in their fabrication. In PEGADIS, we propose a solution to this issue, based on the direct epitaxial growth of platelets of dimensions equal to that of the foreseen µ-LED. The method relies on the pendeo-epitaxial growth of the platelet on an array of deformable nano-pillars, the number and period of which determine the overall dimension of the µ-LEDs. This localised growth method has multiple advantages: no etching is necessary, pillars deformable at the growth temperature prevent the formation of coalescence dislocations, and no cracks are present in the platelet due to the pillars cracking first and releasing the stress. Arrays of micro-LEDs fabricated this way will be used for a first demonstration of a high-resolution high brilliance display.