Nanodamascene metal-insulator-metal single electron transistor prepared by atomic layer deposition of tunnel barrier and subsequent reduction of metal surface oxide

We present an experimental demonstration of a metallic single electron transistor fabricated using plasma enhanced atomic layer deposition (PEALD) of tunnel barrier dielectric followed by reduction of the metal surface that was oxidized during ALD. We found that ALD deposition of a thin SiO₂ layer results in the formation of NiO on the surface of Ni that significantly increases the effective tunnel barrier thickness in Ni-SiO₂-Ni tunnel junctions. We demonstrate that NiO can be fully reduced to Ni by annealing in a 95% Ar - 5% H₂ ambient at 400°C.