CORRELATED ISLAND NUCLEATION IN LAYER-BY-LAYER GROWTH

Temporal correlations of nucleation events in layer-by-layer growth ar e studied by simulating a one dimensional model. In order to focus on fluctuations due to the nucleation process, deposition and diffusion a re treated deterministically. The correlations decay algebraically wit h effective exponents depending on the order of the nucleations in a l ayer. The autocorrelation function of all nucleation events decays as t(-1.35) with time t. In spite of these correlations, the correspondin g randomness in the growth process does not lead to a roughening of th e surface. The reason is that stochastic nucleation implies only conse rved current fluctuations.