Mechanical behaviour of semiconductors in terms of dislocation dynamics

Dynamic properties of dislocations in silicon and some compound semiconductors such as GaAs and InP are compared with each other. Macroscopic stress-strain characteristics during yielding of these materials measured by means of tensile or compressive deformation tests under a constant strain rate are also compared. It is shown that the latter characteristics are deduced successfully with a theoretical model based on the former knowledge of individual dislocations characteristic of each material. A variety of impurities in semiconductor crystals affect the dynamic behaviour of dislocations and, in turn, the mechanical strength of the crystal through two mechanisms: one is modification of the dislocation mobility and the other immobilization of dislocations. It is shown how such impurity effects on the behaviour of individual dislocations are reflected on the macroscopic mechanical properties of semiconductor crystals.