Scaling in film growth by pulsed laser deposition and modulated beam deposition

Abstract

The scalings in film growth by pulsed laser deposition (PLD) and modulated beam deposition (MBD) were investigated by Monte Carlo simulations. In PLD, an atomic pulse beam with a period t(0) were deposited instantaneously on a substrate, whereas in MBD, adatoms were deposited during a short time interval t(1) (0≤t(1)≤t(0)) within each period. If t(1)=0, MBD will be identical to PLD and, if t(1)=t(0), MBD will become usual molecular beam epitaxy (MBE). Specifically, logarithmic scaling was investigated for the nucleation density reported for PLD, and the scaling of island density was studied regarding the growth for 0<t(1)<t(0) in MBD. It was found that the logarithmic scaling held for the nucleation density when growing islands were fractal-like but the quality of data collapsing became worse when islands were compact by adatom diffusion along the edges of islands. A crossover behavior from PLD growth to MBE growth was observed as t(1) increased. The phase diagram was also presented.