Vertically and laterally self-aligned double layer of nanocrystals in nanopatterned dielectric layer for nanocrystal floating gate memory device

摘要

The formation of a vertically and laterally self-aligned double layer of CdSe colloidal nanocrystals (NCs) in a nanopatterned dielectric layer on Si substrate was demonstrated by a repeating dip-coating process for NC deposition and atomic layer deposition (ALD) of _(Al2) O_3 layer. A nanopatterned SiO_2 /Si substrate was formed by patterning with a self-assembled diblock copolymer. After the selective deposition of the first NC layer inside the SiO2 nanopattern by dip-coating, an Al_2 O _3 interdielectric layer and the second NC layer in the Al_2 O_3 nanopattern were sequentially deposited. The capacitance-voltage measurement of an Al-gate/ALD- Al_2 O_3 (25 nm) /second-CdSe-NCs/ ALD-Al_2 O_3 (2 nm) /first-CdSe -NCsanopatterned- SiO_2 (15 nm) /p-Si substrate structure showed the flatband voltage shift through the charge transport between the gate and NCs.