Low-Temperature NiSi Formation via Microwave Annealing for Stable Metal-Induced Lateral Crystallization in 3D NAND Flash Memory

This study introduces a novel Metal-Induced Lateral Crystallization (MILC) method, enhanced by a low-temperature pre-Microwave Annealing (MWA) step, for 3D NAND flash memory. Conventional MILC faces uneven growth due to simultaneous nucleation and grain growth, worsened in confined Si channels because crystalline Si (c-Si) whiskers with Ni silicide nodule fronts block each other during directional growth, limiting the availability of Ni for crystallization. Therefore, we conduct a pre-MWA step to promote the formation of NiSi while suppressing MILC progression caused by the transformation into <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NiSi}_{2}$</tex>, resulting in synchronized MILC growth during the subsequent annealing step. This method ensures stable MILC in 3D NAND flash memory, offering reliable approach for advanced memory technologies.