The effect of a modulated flux on the growth of thin films

TL;DR

This paper investigates how modulating the atomic flux during thin film deposition affects film growth and morphology, combining scaling analysis and simulations to understand the underlying mechanisms.

Contribution

It introduces a model predicting island density changes with flux modulation frequency, validated by simulations, applicable to pulsed-source thin film growth.

Findings

Chopped flux alters film morphology.

Scaling analysis predicts island density behavior.

Simulations confirm theoretical predictions.

Abstract

Thin films are usually obtained by depositing atoms with a continuous flux. We show that using a chopped flux changes the growth and the morphology of the film. A simple scaling analysis predicts how the island densities change as a function of the frequency of the chopped flux in simple cases where aggregation is irreversible. These predictions are confirmed by computer simulations. We show that the model can be used to obtain information on the diffusion or the evaporation of the adatoms. The model is also useful to understand the growth of thin films prepared by pulsed sources.