Evolution of SiO2/Ge/HfO2(Ge) multilayer structure during high temperature annealing

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ARSLANTUNALI ŞAHİN D., YILDIZ İ., Gencer A. I., AYGÜN ÖZYÜZER G., Slaoui A., TURAN R.

THIN SOLID FILMS, vol.518, no.9, pp.2365-2369, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 518 Issue: 9
  • Publication Date: 2010
  • Doi Number: 10.1016/j.tsf.2009.09.156
  • Journal Name: THIN SOLID FILMS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2365-2369
  • Keywords: Ge, Segregation, HfO2, XPS, Depth profiling, Raman spectroscopy, GE NANOCRYSTALS, HFO2
  • Middle East Technical University Affiliated: Yes

Abstract

Use of germanium as a storage medium combined with a high-k dielectric tunneling oxide is of interest for non-volatile memory applications The device structure consists of a thin HfO2 tunneling oxide with a Ge layer either in the form of continuous layer or discrete nanocrystals and relatively thicket SiO2. layer functioning as a control oxide In this work, we Studied interface properties and formation kinetics in SiO2/Ge/HfO2(Ge) multilayer structure during deposition and annealing This material structure was fabricated by magnetron sputtering and studied by depth profiling with XPS and by Raman spectroscopy It was observed that Ge atoms penetrate into HfO2 layer during the deposition and segregate out with annealing This is related to the low solubility of Ge In HfO2 Which is observed in other oxides as well Therefore, Ge out diffusion might be an advantage in forming well controlled floating gate on top of HfO2. In addition we observed the Ge oxidation at the interfaces, where HfSiOx formation is also detected (C) 2009 Elsevier B.V. All rights reserved