Realization of a 2H–Si microneedle with an ultrafast growth rate of 6.7 × 104 Å·s−1

Abstract

Nanomaterials have facilitated the development of innovative technologies in various industries. However, most research has been limited to nanoscale phenomena, and the effects of nanomaterials on microscale crystal growth remain obscure. In this study, we demonstrated a straight 2H-Si microneedle with a longitudinal growth rate of 6.7 × 104 Å·s−1, which could not be explained by conventional crystal growth mechanisms, through AlN nanowires. The AlN nanowires were grown using the hydride vapor-phase epitaxy method, which induced the formation of Al membranes when NH3 supply was ceased. At this time, an elliptical Al membrane was created within 0.166 s, in accordance with the principle of Plateau-Rayleigh instability. The average spacing of the Al membrane was 4 μm, and approximately 10 000 elliptical Al membranes absorbed SiCl almost simultaneously to form a 40 mm 2H-Si microneedle within 100 min of growth time. Therefore, we realized straight 2H-Si microneedles with a growth rate of 6.7 × 104 Å·s−1. Differing from the conventional growth mechanism, this new growth method sheds light on the mechanism by which nanoscale phenomena contribute to the growth of microscale crystals. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.