In this work we report the results of the synthesis and structural and optical characterization of heterostructures SiOx/Ge/SiOx by reactive RF sputtering. The characteristics of germanium along with its compatibility with silicon technology and the sensitivity of its band structure to confinement confer a high attractive to the synthesis of germanium nanostructures.

The samples were prepared on substrates of p-type Si monocrystalline (1 1 1) and commercial glass by reactive sputtering. The effect of the partial pressure of oxygen and Ge interlayer thickness on the electronic properties of the heterostructure is reported[1]. Structural characterization was carried out by grazing angle X-ray difraction and atomic force microscopy. The electronic properties were studied by UV-Vis transmission, infrared and Raman spectroscopies. Surface roughness was quantified by atomic force microscopy. X-ray diffraction showed the amorphous characteristics of the heterostructures. UV-vis spectroscopy results do not presented relevant differences with respect to those from SiO2 reference samples.

The Raman spectra shown modes associated to germanium indicating the formation of low dimensionality germanium particles embedded in an amorphous phase. Ellipsometry and electronic transmission micrographs confirm the presence of Ge nanoparticles. Ohmic contacts were deposited in a van der Pauw geometry using AuSb. Temperature dependent Hall (T-Hall) measurements were done between 35K and 373K, using the van der Pauw method. The results indicate low resistivity values that could be explained due to the formation of a two dimensional electron gas o the presence of mini bands due to the quantum dots interaction.

  

  

[1] E. Mota-Pineda, M. Meléndez-Lira, M. Zapata-Torres, A. Pérez-Centeno, M. A. Santana-Aranda and P. del Angel. Semicond. Sci. Technol. 24 ,105028 (2009).