Structural and electrical studies of ultrathin layers with Si0.7Ge0.3 nanocrystals confined in a SiGe/SiO2 superlattice

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Vieira, EMF (Author) Other; Martin Sanchez, J (Author) Other; Rolo, AG (Author) Other; Parisini, A (Author) Other; Buljan, M (Author) Other; Capan, I (Author) Other; Alves, E (Author) Other; Barradas, NP (Author) Other; Conde, O (Author) Other; Bernstorff, S (Author) Other; Chahboun, A (Author) Other; Levichev, S (Author) Other; Gomes, MJM (Author) Other

Journal

Title: Journal of Applied Physics

Vol. 111

ISSN: 0021-8979

Publisher: American Institute of Physics

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 11 Citations

Other information

Authenticus ID: P-002-A2M

DOI: 10.1063/1.4722278

Abstract (EN): In this work, SiGe/SiO2 multi-layer (ML) films with layer thickness in the range of a few nanometers were successfully fabricated by conventional RF-magnetron sputtering at 350 degrees C. The influence of the annealing treatment on SiGe nanocrystals (NCs) formation and crystalline properties were investigated by Raman spectroscopy and grazing incidence x-ray diffraction. At the annealing temperature of 800 degrees C, where well defined SiGe NCs were observed, a thorough structural investigation of the whole ML structure has been undertaken by Rutherford backscattering spectroscopy, grazing incidence small angle x-ray scattering, high resolution transmission electron microscopy, and annular dark field scanning transmission electron microscopy. Our results show that the onset of local modifications to the ML composition takes place at this temperature for annealing times of the order of a few tens of minutes with the formation of defective regions ill the upper portion of the ML structure. Only the very first layers over the Si substrate appear immune to this problem. This finding has been exploited for the fabrication of a defect free metal-oxide-semiconductor structure with a well-defined single layer of SiGe NCs. A memory effect attributed to the presence of the SiGe NCs has been demonstrated by high frequency capacitance-voltage measurements. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4722278]

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9