Nb Josephson Junction Fabrication

Fabrication and characterization of Nb/AlOx/Nb Josephson junctions.

The Nb Josephson Junction (JJ) devices were fabricated using:

  • A multilayer stack structure of Al pad / Nb / AlOx / Nb / SiO2 / Si substrate.
  • The process involved thin-film deposition, oxidation, E-beam lithography and photolithography steps.

Nb Josephson Junction fabrication process showing key lithography and etching steps (details not mentioned for IP purposes)

(a) Fabricated Nb/AlOx/Nb Josephson Junction chip. (b) Wire-bonded JJ device mounted on a chip carrier for low-temperature measurements in a dilution refrigerator.

These junctions form the fundamental building blocks for superconducting qubits and microwave resonator coupling experiments, enabling precise studies of quantum coherence and nonlinear dynamics at millikelvin temperatures.