An efficient method based on molecular beam epitaxy has been developed to integrate an epitaxial Ge quantum well buried into a single crystalline rare earth oxide. The monolithic heterostructure comprised of Gd2O 3-Ge-Gd2O3 grown on an Si substrate exhibits excellent crystalline quality with atomically sharp interfaces. This heterostructure with unique structural quality could be used for novel nanoelectronic applications in quantum-effect devices such as nanoscale transistors with a high mobility channel, resonant tunneling diode/transistors, etc. A phenomenological model has been proposed to explain the epitaxial growth process of the Ge layer under oxide encapsulation using a solid source molecular beam epitaxy technique. © 2009 IOP Publishing Ltd.