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Molecular beam epitaxy of Dy2O3 thin films grown on Ge(001) substrates using SrGe buffer layers

Students & Supervisors

Student Authors
Tarifuzzaman Riyad
BSc in Electrical & Electronic Engineering, FE
Supervisors
Md. Nurul Kabir Bhuiyan
Senior Assistant Professor, Faculty, FST

Abstract

Molecular Beam Epitaxy of Dy2O3 thin films grown on Ge(001) substrates using SrGe buffer layers Tarifuzzaman Riyad1*, Md. Nurul Kabir Bhuiyan1,2, Mariela Menghini2, Jin Won Seo3 and Jean-Pierre Locquet2 1Department of Physics, American International University-Bangladesh, 408/1, Kuratoli Road, Khilkhet, Dhaka 1229, Bangladesh 2Department of Physics and Astronomy, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001, Leuven, Belgium 3Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B-3001, Leuven, Belgium *Email: tarifuzzaman.riyad@gmail.com The high-κ Dy2O3 epitaxy layers grow on Ge(001) substrates with different orientations [1]. Sr-germanide templates were used to fabricate Ge-based MOSFET devices. Dy2O3 thin layers were grown on Ge(001) substrates using SrGex buffer layers by MBE and the quality of epitaxy layers are studied by RHEED, XRD, XRR, and AFM. The 6 Å and 12 Å Sr layers were first grown on GeO2/Ge(001) at 400°C and followed by post-annealing at 650°C. RHEED patterns show that an amorphous Sr layer grows on GeO2/Ge at 400°C. After post-annealing at 650°C, RHEED streaky patterns indicate a transition from the amorphous to crystalline SrGex structure with smooth surfaces. XRD peaks for SrGex thin films are observed at 2θ =42.67° and 52.23° corresponding to the (200) and (220) diffractions. The interplanar spacing corresponding to the (200) and (220) diffractions are determined to be 2.1192 Å and 1.735 Å, respectively. Hence, the lattice parameters are estimated to be a = 4.91 Å, b = 4.23 Å, and c = 3.47 Å. These findings confirm that the orthorhombic SrGe structure is formed [2]. Finally, Dy2O3 thin films were grown on SrGe/Ge at 400°C. RHEED and XRD results show that the epitaxial cubic Dy2O3 layer is fully relaxed on the SrGe passivation layer on Ge(001) substrates with only a single domain (011) orientation [3]. The thickness of the Dy2O3 epitaxy layer is 228 Å as confirmed by XRR and is 131 Å as confirmed by XRD. The surface of the Dy2O3 epitaxy layer is very smooth with a root mean square roughness of 4.58 Å as confirmed by AFM. References: [1] Md. Nurul Kabir Bhuiyan et al, Microelectronic Engineering, 88 (2011) 411. [2] F. Merlo et al, Journal of the Less Common Metals, 13 (1967) 603. [3] Md. Nurul Kabir Bhuiyan et al, Materials Research Society, 1252 (2010) I03.

Keywords

Dy2O3 epitaxy layer SrGe buffer layer Ge(001) substrates molecular beam epitaxy RHEED XRD XRR and AFM

Publication Details

  • Type of Publication: Conference
  • Conference Name: International Conference on Physics-2024
  • Date of Conference: 05/09/2024 - 05/11/2024
  • Venue: Atomic Energy Centre, Dhaka 1000, Bangladesh
  • Organizer: Bangladesh Physical Society
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