Realization of Ultrahigh Quality InGaN Platelets to be Used as Relaxed Templates for Red Micro-LEDs

In this work, arrays of predominantly relaxed InGaN platelets with indium contents of up to 18%, free from dislocations and offering a smooth top c-plane, are presented. The InGaN platelets are grown by metal-organic vapor phase epitaxy on a dome-like InGaN surface formed by chemical mechanical polishing of InGaN pyramids defined by 6 equivalent {101¯ 1} planes. The dome-like surface is flattened during growth, through the formation of bunched steps, which are terminated when reaching the inclined {101¯ 1} planes. The continued growth takes place on the flattened top c-plane with single bilayer surface steps initiated at the six corners between the c-plane and the inclined {101¯ 1} planes, leading to the formation of high-quality InGaN layers. The top c-plane of the as-formed InGaN platelets can be used as a high-quality template for red micro light-emitting diodes.