Atomic layer deposition of aluminum doped zinc-oxide thin films for zero-index optics

ORAL

Abstract

Ultra-thin and ultra-smooth transparent conducting oxide materials with epsilon-near-zero (ENZ) (real part of material permittivity crosses zero) properties are important for zero-index optical applications, for instance, perfect absorption and advanced quantum/nonlinear ENZ applications. In this paper, we demonstrate the use of atomic layer deposition (ALD) technique to fabricate high quality aluminium doped zinc oxide (AZO) nanofilms with precisely controlled thicknesses and desired optical properties in the near-infrared spectral region.

The ultra-thin (< 100 nm) and ultra-smooth (RMS roughness ~ 1.5 nm) AZO films are synthesized by ALD using diethylzinc (DEZ), trimethylaluminum (TMA), and water precursors on two different substrates (silicon and fused silica). Spectroscopic ellipsometry is used to characterize the optical and electrical properties of the deposited AZO films. We show that the ENZ frequency and the growth rate of AZO are strongly dependent on the substrate, and they can be precisely tuned by deposition parameters such as dopant ratio and deposition temperature. These ALD grown AZO nano-layers with tunable ENZ frequencies enable the development of ultra-compact and tunable metamaterial devices.

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Presenters

  • Sudip Gurung

    Department of Physics and Baylor Research and Innovation Collaborative (BRIC), Baylor University, Waco, TX 76798, United States, Baylor University, Department of Physics, Baylor University, Waco, TX 76798, United States

Authors

  • Sudip Gurung

    Department of Physics and Baylor Research and Innovation Collaborative (BRIC), Baylor University, Waco, TX 76798, United States, Baylor University, Department of Physics, Baylor University, Waco, TX 76798, United States

  • Subhajit Bej

    Baylor University

  • Garand Tyson

    Stanford University

  • Aleksei Anopchenko

    Department of Physics and Baylor Research and Innovation Collaborative (BRIC), Baylor University, Waco, TX 76798, United States, Department of Physics and Baylor Research and, Baylor University, Department of Physics, Baylor University, One Bear Place #97316, Waco, TX 76798, Department of Physics, Baylor University, Waco, TX 76798, United States

  • Howard Ho Wai Lee

    Baylor Univ, Texas A&M Univ, Department of Physics and Baylor Research and Innovation Collaborative (BRIC), Baylor University, Waco, TX 76798, United States, The Institute for Quantum Science and Enginee, Baylor University, Department of Physics, Baylor University, One Bear Place #97316, Waco, TX 76798, Institute for Quantum Science and Engineering, Texas A&M University, College Station, TX 778, Department of Physics, Baylor University, Waco, TX 76798, United States, The Institute for Quantum Science and Engineering, Texas A&M University College Station, TX 77843, Un