Misfit Dislocations In Znse Grown On Vicinal Si(001) Substrates

High resolution electron microscopy (HREM) has been used to study misfit dislocations of ZnSe films grown on vicinal Si(001) substrates tilted 4-degrees towards the [110BAR] axis. In images taken with the electron beam parallel to the [110BAR] direction, 60-degrees dislocations were found to predominate whereas mostly Lomer dislocations or closely spaced 60-degrees dislocations (separated by <2 nm) were observed in images taken in the orthogonal direction. A model is presented here to explain the formation of the asymmetric dislocation structure on the basis of mechanisms for propagation and formation of misfit dislocations.