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Keywords:

  • 61.46.−w;
  • 71.20.Eh;
  • 71.55.Cn;
  • 81.05.Cy;
  • 81.15.Hi

Abstract

The ability to integrate crystalline metal oxide dielectric barrier layers into silicon structures can open the way for a variety of novel applications which enhances the functionality and flexibility ranging from high-K replacements in future MOS devices to oxide/silicon/oxide heterostructures for nanoelectronic application in quantum-effect devices. We present results for crystalline gadolinium oxides on silicon in the cubic bixbyite structure grown by solid source molecular beam epitaxy. Additional oxygen supply during growth improves the dielectric properties significantly. Experimental results for Gd2O3-based MOS capacitors grown under optimized conditions show that these layers are excellent candidates for application as very thin high-K materials replacing SiO2 in future MOS devices. Epitaxial growth of lanthanide oxides on silicon without any interfacial layer has the advantage of enabling defined interfaces engineering. We will show that the electrical properties of epitaxial Gd2O3 thin films on Si substrates can further be improved significantly by an atomic control of interfacial structures. Finally, we will present a new approach for nanostructure formation which is based on solid-phase epitaxy of the Si quantum-well combined with simultaneous vapor-phase epitaxy of the insulator on top of the quantum-well. Ultra-thin single-crystalline Si buried in a single-crystalline insulator matrix with sharp interfaces was obtained by this approach on Si(111). In addition, structures consisting of a single-crystalline oxide layer with embedded Si nanoclusters for memory applications will also be demonstrated. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)