MISFIT DISLOCATIONS IN ZNSE GROWN ON VICINAL SI(001) SUBSTRATES

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