A prospective submonolayer template structure for integration of functional oxides with silicon

Abstract

Epitaxial integration of oxides with the ubiquitous silicon technological platform promises devices with dreamed-of functionality but is difficult to achieve due to chemical processes at the Si/oxide interface. The standard approach suggests a protective template – a surface superstructure of SrSi2 stoichiometry; still, only a handful of oxides couple to Si with atomically abrupt interface. We advocate an alternative approach – the use of metal-rich submonolayer templates as a general recipe, in particular, robust 1×5 reconstructions of Sr and Eu on Si. Their fail-safe synthesis is reported, diffraction techniques and electron microscopy reveal the structure and thermal stability of the reconstructions. The surface protection is discussed in terms of oxidation kinetics. The advantages of the new templates are demonstrated recruiting the example of the paradigmatic spintronic system EuO/Si.