APL Materials (Jul 2024)

Effect of ion irradiation on superconducting thin films

  • Katja Kohopää,
  • Alberto Ronzani,
  • Robab Najafi Jabdaraghi,
  • Arijit Bera,
  • Mário Ribeiro,
  • Dibyendu Hazra,
  • Jorden Senior,
  • Mika Prunnila,
  • Joonas Govenius,
  • Janne S. Lehtinen,
  • Antti Kemppinen

DOI
https://doi.org/10.1063/5.0202851
Journal volume & issue
Vol. 12, no. 7
pp. 071101 – 071101-8

Abstract

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We demonstrate ion irradiation by argon or gallium as a wafer-scale post-processing method to increase disorder in superconducting thin films. We study several widely used superconductors, both single-elements and compounds. We show that ion irradiation increases normal-state resistivity in all our films, which is expected to enable tuning their superconducting properties, for example, toward a higher kinetic inductance. We observe an increase in superconducting transition temperature for Al and MoSi and a decrease for Nb, NbN, and TiN. In MoSi, ion irradiation also improves the mixing of the two materials. We demonstrate the fabrication of an amorphous and homogeneous film of MoSi with uniform thickness, which is promising, for example, for superconducting nanowire single-photon detectors.