Mask-free selective GaN growth driven by LT-GaN redistribution on patterned CrN buffers

초록

Gallium nitride (GaN)-based micro-light-emitting diodes (LEDs) have attracted attention as next-generation display devices owing to their low-power and long-life characteristics. In particular, through selective-area growth (SAG) of core-shell structures, m-plane light emission and quantum-confined Stark effect mitigation can be achieved simultaneously. The realization of such structures requires a precise SAG process and an efficient liftoff technique. In this study, a maskless chromium nitride (CrN) dot-patterned substrate was fabricated to implement a selective GaN growth process, and the effect of the initial low-temperature GaN (LT-GaN) layer on SAG was systematically analyzed. By evaluating the surface properties at each growth stage, it was confirmed that the CrN dot region maintained a high-polarity component and surface energy and provided favorable conditions for the selective nucleation of GaN precursors. This is attributed to selective GaN growth exclusively on the CrN dots, resulting from the combined effect of LT-GaN particle reorganization and the surface thermodynamic properties of CrN. This study is experimentally demonstrated for the feasibility of mask-free III-nitride selection growth technology, which can be used as a core technology for future micro-LED processes.

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