(2+1)-dimensional stochastic growth model and its application to some experimental observations

A (2+1)-dimensional stochastic growth model is proposed in order to understand various experimental observations at low temperature growth. The model includes step attached adatom hopping in the upward direction to provide a source of additional particle current. The flexibility obtained due to additional current control allows one to express most of the experimental observations within the framework of this model. It is argued that the time evolution exponent beta for surface roughness is >0.5 only if upward hops are included. Simulations using this model are shown to be qualitatively consistent with the observations for homoepitaxial growth on Cu(100) and Ge(100) at different temperatures.