Stable chalcogenide Ge–Sb–Te heterostructures with minimal Ge segregation

• Published in: Scientific reports Vol. 14; no. 1; pp. 15713 - 8
• Main Authors: Bertelli, Marco, Sfuncia, Gianfranco, De Simone, Sara, Diaz Fattorini, Adriano, Calvi, Sabrina, Mussi, Valentina, Arciprete, Fabrizio, Mio, Antonio M, Calarco, Raffaella, Longo, Massimo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 08.07.2024; Nature Publishing Group UK; Nature Portfolio
• Subjects: Alloys; Annealing; Crystallization; Energy loss; Ge-rich; GST; Internet of Things; PCM; Physical properties; Raman spectroscopy; Sb2Te3; Spectroscopy; Spectrum analysis; Sputtering; Temperature; Transmission electron microscopy; X-ray diffraction; X-ray fluorescence
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-66441-y

Abstract Matching of various chalcogenide films shows the advantage of delivering multilayer heterostructures whose physical properties can be tuned with respect to the ones of the constituent single films. In this work, (Ge–Sb–Te)-based heterostructures were deposited by radio frequency sputtering on Si(100) substrates and annealed up to 400 °C. The as-deposited and annealed samples were studied by means of X-ray fluorescence, X-ray diffraction, scanning transmission electron microscopy, electron energy loss spectroscopy and Raman spectroscopy. The heterostructures, combining thermally stable thin layers (i. e. Ge-rich Ge 5.5 Sb 2 Te 5 , Ge) and films exhibiting fast switching dynamics (i. e. Sb 2 Te 3 ), show, on the one side, higher crystallization-onset temperatures than the standard Ge 2 Sb 2 Te 5 alloy and, on the other side, none to minimal Ge-segregation.