[18a-222-1~11] 12.6 Nanobiotechnology

[18a-222-4] Atomic layer Al₂O₃ thickness to fine-tuning pore surface charge

〇Tomoki Hayashida¹, Kazumichi Yokota¹, Makusu Tsutsui¹, Masateru Taniguchi¹ (1.ISIR)

Keywords:micropore, Atomic Layer Deposition

We fabricated a micropore device coating with Al₂O₃ membrane using Atomic layer deposition (ALD). We formed Al₂O₃ membrane in the range of 1nm to 20 nm on a Si₃N₄ micropore device. Using this device, we measured ionic current changes when particles pass through micropores and investigated pulse size and changes of detection frequency comparing each Al₂O₃ thickness. When we used carboxylated-polystyrene beads (φ0.78 µm), pulse size changed depending on Al₂O₃ layer thickness. The zeta potential measurement on the surface of the Si₃N₄ / Al₂O₃ membrane revealed that the surface potential changes with accuracy of less than 1 mV depending on the thickness of the coated Al₂O₃, by the preserved influence of the negative charge on the Si₃N₄ surface.