Physical-mechanical characteristics of monocrystalline Si1-xGex (x≤0,02) solid solutions

2^nd International Conference and Exhibition on Materials Science & Engineering

October 07-09, 2013 Hampton Inn Tropicana, Las Vegas, NV, USA

I. R. Kurashvili, E. E. Sanaia, A. V. Sichinava, G. V. Bokuchava and G. Sh. Darsavelidze

Accepted Abstracts: J Material Sci

Abstract :

Si-Ge solid solutions (bulk poly-and monocrystalline samples, thin films) are characterized by high perspectives for application in semiconductor devices, in particular, optoelectronics and microelectronics. In this light complex, studying of structural state of the defects and structural-sensitive physical properties of Si-Ge solid solutions depending on the contents of Si and Ge components is very important. Present work deals with the investigations of microstructure, electrophysical characteristics, microhardness, internal friction and shear modulus of Si 1-x Ge x (x≤0,02) bulk monocrystals conducted at room temperatures. Si-Ge bulk crystals were obtained by Czochralski method in [111] crystallographic direction. Investigated monocrystalline Si 0,995 Ge 0,005 , Si 0,99 Ge 0,01 and Si 0,98 Ge 0,02 samples are characterized by p-type conductivity and carriers concentration is 5.10 14 - 1.10 15 cm -3 , dislocation density is 5.10 3 -1.10 4 cm -2 , microhardness according to Vickers method is 900-1200 kg/mm 2 , and shear modulus is 4100-4300 kg/mm 2 . Investigated samples are characterized with 0.5х0.5х (10-15) mm 3 sizes, oriented along [111] direction at torsion oscillations ≈1 Hz, multistage changing of internal friction and shear modulus has been revealed in an interval of strain amplitude of 10- 5 -5 .10 -3 . Critical values of strain amplitude have been determined at which hysteretic changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also determined. Tendency to decrease dynamic mechanical characteristics is shown with increasing Ge content in Si-Ge solid solutions. Observed changes are discussed from the point of view of interaction of various dislocations with point defects and their complexes in a real structure of Si-Ge solid solutions.

Biography :

I. R. Kurashvili has completed her Ph.D. at the age of 28 years from Georgian Technical University. She is senior scientific worker of Sukhumi Institute of Physics and Technologies (Georgia, Tbilisi). She has published more than 25 papers in reputed journals.