Kim, Kyunghwan Choi, Sunhae Bong, Haekyun Oh, Jungwoo 2024-11-30T06:00:25Z 2024-11-30T06:00:25Z 2024-11-30 2025-03 1613-6810 https://pubs.kist.re.kr/handle/201004/151209 Metal-assisted chemical etching (MACE), a wet-based anisotropic etching process for semiconductors, has emerged as an alternative to plasma-based etching. However, using noble metal catalysts in MACE limits the implementation of complementary metal-oxide-semiconductor (CMOS) processes. This study explores Si etching using an ultrathin Ni catalyst as a novel approach for MACE. The thickness of the Ni catalyst emerges as a critical parameter, with 1 nm of Ni proving to be the optimal thickness to achieve smooth and deep etching. Unlike conventional MACE methods, the ultrathin Ni catalyst enables Si etching without strong oxidants. Wafer-scale Si etching demonstrates the versatility of the ultrathin Ni catalyst in producing various microstructures. It is found that the ultrathin Ni/Si interfacial state plays a crucial role in influencing the Si reactivity, lowering the barrier for Si oxidation. CMOS-compatible and cost-efficient ultrathin Ni makes MACE a promising alternative for semiconductor nanofabrication. This study pioneers MACE using an ultrathin non-noble metal catalyst, offering valuable insights for researchers in this field. English Wiley - V C H Verlag GmbbH & Co. Modified Si Oxidation Behavior by Ultrathin Ni Catalyst Enabling Oxidant-Less Metal-Assisted Chemical Etching Article 10.1002/smll.202409091 1 Small, v.21, no.11 Small 21 11 Y scie scopus 001357385900001 2-s2.0-85207969726 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article HIGH-ASPECT-RATIO SILICON NANOSTRUCTURES NANOWIRES ARRAYS metal-assisted chemical etching (MACE) nanostructure silicon ultrathin nickel CMOS-compatible