Dislocation behaviour in strained layer interfaces

摘要

The origin and energetics of misfit dislocations in interfaces between misfitting layers are reviewed. Experimental results on the distribution of misfit dislocation (MD) spacings in GaAs-based systems reveal the random nucleation behaviour of MDs and the gradual evolution of populations of 90 deg edge dislocations. Etch pit results indicate that dislocation multiplication becomes significant only when strained layers exceed a thickness of 4h_c. The contribution of MDs to the formation of cross-hatch is clarified by observations of layers grown on vicinal substrates.