1/f noise and two-level systems in MBE-grown Al thin films

ORAL

Abstract

Aluminum thin films play a critical role in electronic and quantum devices, where two-level systems (TLSs) can limit performance. Molecular beam epitaxy (MBE) offers a promising route to reduce TLS densities in Al films. We investigated the energy distribution of TLS densities, g(E), in 10-nm-thick MBE-grown and electron-beam-evaporated Al films via 1/f noise measurements from 80 to 360 K. At 300 K, the MBE-grown films exhibited noise magnitudes about three times lower than those of the evaporated films, corresponding to roughly an order-of-magnitude reduction in g(E). These results indicate that the observed 1/f noise originates from thermally activated TLSs associated with grain boundaries, consistent with previously established observations [1].

*This work was supported by the National Science and Technology Council of Taiwan through Grant Nos. 113-2119-M-007-008 (Y.H.G.L., M.H., and J.J.L.), 112-2112-M-007-051 (J.K.), 111-2112-M-A49-034 (J.J.L.), 110-2112-M-A49-033-MY3, and 113-2112-M-A49-036 (S.-S.Y.). Y.-H.G.L. acknowledges the support from the Taiwan Ministry of Education Yushan Young Scholar Fellowship. S.S.Y. acknowledges the support from the Taiwan Ministry of Education through the Higher Education Sprout Project of the NYCU.

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Publication: 1) Shouray Kumar Sahu et al., "1/f noise and two-level systems in MBE-grown Al thin films," APL Mater. 13, 071120 (2025)

Presenters

  • Shouray Kumar Sahu

    • International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 30010

Authors

  • Shouray Kumar Sahu

    • International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 30010

  • Yen-Hsun Glen Lin

    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 106319

  • Kuan-Hui Lai

    • National Taiwan University
    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 106319

  • Chao-Kai Cheng

    • National Taiwan University
    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 106319

  • Chun-Wei Wu

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010

  • Elica A Heredia

    • International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 30010

  • Ray-Tai Wang

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010

  • Yen-Hsiang Lin

    • National Tsing Hua University
    • Department of Physics, National Tsing Hua University, Hsinchu 300044

  • Juainai Kwo

    • National Tsing Hua University
    • National TsingHua University
    • Department of Physics, National Tsing Hua University, Hsinchu 300044

  • Minghwei Hong

    • National Taiwan University
    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 106319

  • Juhn-Jong Lin

    • Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010

  • Sheng-Shiuan Yeh

    • National Yang Ming Chiao Tung University
    • International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 30010