GaN growth by MOVPE on patterned SOI substrates: from high-quality GaN platelets to micro LEDs

This work presents the use of nanopendeo-epitaxy of gallium nitride (GaN) on Silicon-On-Insulator (SOI) nano-pillars to produce 20x20 μm2 low threading dislocation density (TDD) GaN platelets, with a TDD <3×108 cm−2 for their subsequent use as templates for GaN microLEDs. After discussing the general growth strategy, the correlation between optical and structural characterizations will illustrate the behavior of dislocations from the initial GaN/SOI pillars to the GaN platelets surface. Finally, we demonstrate that a state of the art TDD for GaN on silicon lower than 3×108 cm−2 can be achieved by changing the growth mode in Metal Organic Vapor Phase Epitaxy (MOVPE).