High-Uniformity GaN Micropyramids and Platelets by Selective Area Growth

The development of uniform GaN micropyramids and platelets via selective area growth is a critical step toward advancing III-nitride device technologies, particularly for microlight-emitting diode applications. This work investigates the origins of morphological nonuniformity in micropyramids and microplatelets grown by metal–organic chemical vapor deposition (MOCVD). We observe that a direct one-step growth approach leads to significant growth rate inhomogeneity across arrays. To shed light on this issue, we examine the mechanisms driving nonuniformity and explore process modifications aimed at mitigating these effects. Building on these insights, we propose a controlled multistep growth strategy that combines sequential growth and thermal treatment phases. This approach is demonstrated to enhance the surface morphology and structural regularity. The work contributes to the broader objective of enabling scalable and high-precision GaN microstructure fabrication for next-generation optoelectronic applications.