Current knowledge concerning macroscopic plasticity (hardness, yield strength) and microscopic plasticity (velocity of individual dislocations) in elemental and IV-IV, III-V or II-VI semiconductors, including GaN, was considered with regard to their mutual correlations. The Vickers hardness of the semiconductor could provide conventional information on the material plasticity over temperatures ranging up to the melting point, over a wide range of size-scales and in various material forms. The hardness, Hv, of diamond- and sphalerite-type semiconductors was related to their temperature dependence, as was the yield strength, τy, giving: Hv = (70-100)τy in the low-temperature region. The yield strengths obtained by normal tensile or compression tests were expressed as a function of the strain rate and temperature. The velocities of various types of dislocation, measured directly in several semiconductors, were described as a function of the stress and the temperature. By analysis of the yield-strength data in terms of the collective motion of dislocations during plastic deformation, the dislocation motion and rate-controlling plastic deformation, were deduced. The activation energy for dislocation motion had a linear relationship to the band-gap energy; depending upon the type of semiconductor.

Hardness, Yield Strength, and Dislocation Velocity in Elemental and Compound Semiconductors. I.Yonenaga: Materials Transactions, 2005, 46[9], 1979-85