← Back to Publications List

Solid Phase Epitaxy of Gd5Ge4 Thin Layers Grown on Ge(001) Substrates

Students & Supervisors

Student Authors
Mst. Maksuda Akter Sraboni
BSc in Electrical & Electronic Engineering, FE
Supervisors
Dr. Md. Nurul Kabir Bhuiyan
Senior Assistant Professor, Faculty, FST

Abstract

Solid Phase Epitaxy of Gd5Ge4 Thin Layers Grown on Ge(001) Substrates Mst. Maksuda Akter Sraboni,1* Md. Nurul Kabir Bhuiyan,1,2 Mariela Menghini,2 Jin Won Seo,3 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: srabonisheikh14@gmail.com Thin layers of Gd5Ge4 were grown on Ge(001) substrates using solid phase epitaxy (SPE) for creating ohmic contacts in CMOS devices. Initially, Gd films were deposited at room temperature (RT), followed by post-annealing at 350°C and 750°C. The structural, morphological, and interfacial properties of the Gd-germanide thin film were extensively investigated using in situ reflection high-energy electron diffraction (RHEED), ex situ X-ray diffraction (XRD) and reflectivity (XRR), atomic force microscopy (AFM), and cross-sectional transmission electron microscopy (TEM). RHEED patterns, XRD patterns, and AFM images indicate that the Gd5Ge4 films transformed into a crystalline phase due to interdiffusion between Gd adatoms and Ge substrates. XRD diffraction peaks are observed at 2θ = 25.94° and 34.11°, corresponding to the (022) and (042) diffractions of the orthorhombic Gd5Ge4 structure. After annealing at 350°C, AFM images indicate the smooth surface of the film with a root mean square value of 2.68Å without any pits. The cross-sectional TEM image shows a crystalline structure at 750°C with an abrupt interface, while containing an amorphous phase at 350°C due to limited adatom mobility.

Keywords

Epitaxy of Gd5Ge4 thin films; Ge(001) substrate; MBE; RHEED; XRD; TEM

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
View on Publisher