https://doi.org/10.15407/jopt.2017.52.128

Optoelectron. Semicond. Tech. 52, 128-134 (2017)

G.P. Gaidar, P.I. Baranskii1

EXPERIMENTAL EVIDENCE OF INVARIABILITY IN THE SHAPE OF n-Ge ISOENERGETIC ELLIPSOIDS INFLUENCED BY STRONG UNIAXIAL ELASTIC STRAINS

Tensoresistance changes in the n-Ge and n-Si crystals of different crystallographic orientations have been investigated in a wide range of the mechanical compressive stresses at 77 K. It has been ascertained that under the influence of strong uniaxial strains the n-Ge isoenergetic ellipsoids shift only relatively to each other in the energy scale, keeping their shape unchanged. It has been found that, under conditions when shear strains are possible, the n-Si isoenergetic ellipsoids change their shape due to the growth of the transverse effective mass of charge carriers with an increase in the mechanical load X. The extrapolation method has been proposed to determine the anisotropy parameter of mobility for n-Si crystals under conditions of shear strains manifestation. This method is very important for practice.

Keywords: germanium, silicon, uniaxial elastic strain, tensoresistance, isoenergetic ellipsoid, anisotropy parameter of mobility.