Dislocation Velocities in GaAs

Abstract

Dislocation velocities in undoped n-type (n=1×1017 cm-3) and Zn-doped p-type (p=3×1018 cm-3) GaAs have been determined by the double-etch technique. In n-type GaAs, α dislocations are about 102 times faster than β dislocations; in p-type GaAs, β dislocations are about 2 to 10 times faster than α dislocations. The velocities of α dislocations in n- and p-type GaAs are roughly equal; the velocities of β dislocations in n-type GaAs are 102 to 103 times smaller than in p-type GaAs. The velocity data can be well described by two theories: the abrupt kink model and the dragging point model. The stress dependence of the activation energy for dislocation motion is successfully described by the abrupt kink model.