A monte carlo study of dislocation growth and etching of crystals

It is well known that screw dislocations are step sources that allow crystals to grow at low driving forces. Growth is accelerated at the outcrop of a screw dislocation generating a spiral hillock. This makes the intersection of a screw dislocation and a crystal surface a so-called velocity source. In this paper the interaction between dislocation growth, 2D-nucleation and misorientation step flow is investigated for a wide range of driving forces by means of Monte Carlo simulations of growth of the Kossel (1 0 0) surface. The interactions between the different growth mechanisms are shown to agree with a general model for velocity source behavior, which allows for a simple analytical expression of the growth rate. This expression can be used in a continuum description of crystal growth. Finally, dislocation etching is studied and compared with dislocation growth.