JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Sun, Z. AU - Deng, X. AU - Liepe, M. AU - Oseroff, T.E. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - Characterization of Atomic-Layer-Deposited NbTiN and NbTiN/AlN Films for SIS Multilayer Structures J2 - Proc. of SRF2021, East Lansing, MI, USA, 28 June-02 July 2021 CY - East Lansing, MI, USA T2 - International Conference on RF Superconductivity T3 - 20 LA - english AB - SIS (superconductor-insulator-superconductor) mul-tilayer structures are proposed designs to repel early flux penetration and ease the impact of defects in SRF cavities. The demonstration of such device physics is strongly affected by the film qualities ’ material struc-ture and composition. Here, we characterized 100 nm NbTiN / 2 nm AlN / bulk Nb SIS structures and investigated the effect of the presence of the AlN layer on the NbTiN film properties. We find that the hcp-structured AlN layer results in a Nb composition gra-dient as a function of film depth, whereas the Nb con-centration remains constant in the NbTiN/Nb samples, which suggests that interface mismatch could induce significant change in NbTiN composition. The surface composition variation further leads to different oxide structures, which might impact the superconducting performance. Our observations indicate that the choice of the insulating layer in SIS structures is critical, and that interface mismatch together with internal strain could deteriorate the superconducting film. PB - JACoW Publishing CP - Geneva, Switzerland SP - 662 EP - 665 KW - interface KW - SRF KW - site KW - cavity KW - superconductivity DA - 2022/10 PY - 2022 SN - 2673-5504 SN - 978-3-95450-233-2 DO - doi:10.18429/JACoW-SRF2021-WEPTEV012 UR - https://jacow.org/srf2021/papers/weptev012.pdf ER -