Bonded interface properties of Nb direct bonding with Si intermediate layer for 3D interconnection of superconducting devices

In this study, Deposited Nb and Si/Nb samples were bonded directly by surface activated bonding method at room temperature. TEM observation of the Nb/Nb interface confirmed an intermediate layer of about 3 nm. A superconducting current of 4–6 mA was observed at 0.3 K in a Si (5 nm) sample deposited on Nb thin film.