Germanium-induced texture and preferential orientation of NiSi1-xGex layers on Si1-xGex
2004 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 70, no 23, 1-11 p.Article in journal (Refereed) Published
NiSi1-xGex films on compressively strained as well as relaxed undoped Si1-xGex epitaxially grown substrates with x=0.06-0.30 on Si(001) wafers have been studied with respect to the relative orientation of film and substrate after annealing at temperatures in the range 400-850 degreesC. Using x-ray diffraction, transmission electron microscopy, and pole-figure measurements, it was found that only the monogermanosilicide phase formed above 450 degreesC and was the only phase still at 850 degreesC. New information regarding the effects of Ge on the silicidation of Ni was also found. Thus, the preferred plane parallel to the surface is (013). Compared to NiSi, Ge suppresses the development of the other planes parallel to the surface except (013). Within this plane, the orientations of the grains pile up in such a way that the configuration NiSi1-xGex//Si1-xGex is avoided, which in the pole-figures leads to broad peaks in-between the substrate  and . In addition, peaks indicating the epitaxial alignment NiSi0.8Ge0.2(+/-21-1) or (+/-2-11)//Si0.8Ge0.2(+/-2+/-20) coupled with NiSi0.8Ge0.2(+/-100)approximate to//Si0.8Ge0.2(+/-100) or (0+/-10) were found. Fine structure in the broad peaks is found to be due to lateral epitaxial alignments between grains along their common grain boundary. Based on the nonexistence of NiGe2, the observations are interpreted in terms of Ge preventing the formation of certain Ni-Ge bonds at the interface between NiSi1-xGex and the Si1-xGex substrate.
Place, publisher, year, edition, pages
2004. Vol. 70, no 23, 1-11 p.
phase-stability, single-crystal, thin-films, nisi
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-23991DOI: 10.1103/PhysRevB.70.235307ISI: 000226112100086ScopusID: 2-s2.0-14044259250OAI: oai:DiVA.org:kth-23991DiVA: diva2:342690
QC 20100525 QC 201109212010-08-102010-08-102012-03-21Bibliographically approved